Tensions are running high in Barcelona. Last month saw a terrorist attack on one of the city’s main thoroughfares, Las Ramblas, which killed a dozen people and injured more than 100. Now, Barcelona and the greater region of Catalonia are a day away from an independence referendum that has pitted the Catalan and Spanish governments against each other in a way unseen since the fall of Francisco Franco’s military dictatorship in the 1970s.

The central government in Madrid is bent on preventing the Oct. 1 referendum: In the last week, Spanish military police have shut down multiple websites associated with the referendum and raided newspaper offices, TV stations, and print shops in search of the ballots and ballot boxes to be used in the vote. The Spanish interior minister has attempted to seize control of the Catalan police. Meanwhile, two ferries docked in Barcelona’s port are housing thousands of riot police that Madrid has said it plans on using to physically stop the vote. Spanish police have arrested at least a dozen members of the Catalan autonomous regional government and others involved with the independence movement, threatening charges of “sedition” and “rebellion.”

Last month, as the referendum fervor was heating up, leading Spanish daily newspaper El Periódico published a document alleging that the CIA had warned the Catalan police about a potential attack in Barcelona. The document stated that three months before the attack, the CIA had warned the Catalan police, the Mossos d’Esquadra, of “unsubstantiated information of unknown veracity” pointing to a summer attack in Barcelona. The document (pictured below) named Las Ramblas as a potential target.

The revelation had huge implications — if true, it would represent a case of gross negligence on the part of the Catalan police and evidence that Catalonia’s president, interior minister, and police chief had lied to the public. But El Periódico’s initial story unraveled quickly: Soon after its publication, local journalists questioned the veracity of the document. Supposedly authored by the CIA, it was plagued with spelling and formatting errors typical of Spanish speakers. Even WikiLeaks founder Julian Assange tweeted that he thought it looked fake.

The publication of the document raises many questions. If it is indeed fake, was it created by El Periódico, or did the newspaper get spun a fabrication by an outside source who was intent on undermining trust in Catalonia’s authorities? Just over one month after the attacks in Barcelona and prior to Catalonia’s impending referendum, The Intercept has delved into the strange case in an effort to shine light on the murky origins of the alleged CIA report.

POLITICA  COMUNICADO  CARTA DEL ESPIONAJE ESTADOUNIDENSE CIA ALERTANDO DEL ATENTADO EN BARCELONA RAMBLAS RAMBLA RAMBLES

The story started as a blip in the live coverage of the attack on Aug. 17, 2017. Less than one hour after a large van had rammed through crowds of people on Las Ramblas, El Periódico published an entry on its live blog stating that the “CIA warned the Mossos two months ago that Barcelona, specifically [Las Ramblas], could be the location of a terrorist attack like the attack that happened today.” At the time, dead bodies were still scattered across the street’s pedestrian center.

El Periódico wasn’t the only Spanish newspaper publishing articles trying to prove that police had been warned of a potential attack. In the days following the incident, for example, El País ran a story stating that Belgian intelligence had alerted the Mossos about one of the attackers earlier this year. But the El País report was quickly debunked. Still, the Spanish and Catalan press were eager for the police negligence story.

El Periódico published the first document on Aug. 31, which it claimed was a section of a CIA report about a potential attack in Barcelona. Days earlier, Catalonia’s president and interior minister had both made public statements saying that there had been no warning from the CIA, in response to El Periódico’s post on the day of the attack.

Josep Lluís Trapero, head of the Mossos, held a press conference to say the same, though he added one small detail — the Mossos did receive a warning in May about a potential attack in Barcelona, but it wasn’t from the CIA and it was sent to all levels of Spanish police. Trapero said that the Mossos, alongside the Spanish national police, military police, and counterterrorism officials, had all determined the notice to be of “very low quality.” And either way, Trapero insisted, El Periódico’s document was false.

Still, the story was picked up all over Spain and internationally. Politicians and journalists accused Catalonia’s president, interior minister, and police chief of lying to the public about the alleged CIA warning. Each of the three officials were responsible for critical aspects of Catalan governance and all three supported the independence movement. With the Oct. 1 referendum looming, the accusations of negligence and misinformation were significant and damaging.

Enric Hernàndez, director of El Periódico, backpedaled in response to questions about the document’s veracity. In an interview with a Catalan radio station on the same day he published the purported CIA warning, Hernàndez stated that the document was authored by the CIA, but said that it was the U.S. National Counterterrorism Center, not the CIA, that had sent the warning to the Catalan police.

Hernàndez added that the warning had also been sent to other Spanish police forces. When asked why he had singled out the Mossos for criticism, he avoided the question. And he bizarrely blamed email encryption for the typos and formatting errors that had appeared in the document.

The following day, Sept. 1, Hernàndez published another article about the alleged CIA warning, including what he called a complete version of the document. The document was similar to the original, with some typos corrected. The accompanying article no longer mentioned the CIA and instead adopted a more generic term: “American intelligence.” Hernàndez said the document had been sent from the National Counterterrorism Center to the Mossos and also to CITCO, Spanish counterterrorism police.

As the backlash continued, Hernàndez revised his story again. The published document, he said, wasn’t an original after all — the newspaper had created it based on the text of the original. Hernàndez maintained that his source had, just before publishing, requested that the original document not be published. So El Periódico mocked-up its own version.

Josep Lluis Trapero, chief of the Catalan regional police "Mossos D'Esquadra" (R) and Interior Minister for the Catalan government Joaquim Forn (L) give a press conference in Barcelona on August 31, 2017.<br /> US security agencies warned Spain in May that the Islamic State group was planning an attack in Barcelona, where the jihadists claimed a deadly van rampage earlier this month, local media said on August 31, 2017. The daily El Periodico de Cataluna reported that the US National Counterterrorism Center (NCTC) alerted Spanish intelligence officers to the threat weeks before a man ploughed his vehicle into crowds of tourists along Barcelona's Las Ramblas boulevard on August 17, killing 14 people. / AFP PHOTO / LLUIS GENE        (Photo credit should read LLUIS GENE/AFP/Getty Images)

Josep Lluis Trapero, chief of the Catalan regional police Mossos D’Esquadra and Interior Minister for the Catalan government Joaquim Forn, left, give a press conference in Barcelona on Aug. 31, 2017.

Photo: Lluis Gene/AFP/Getty Images

Hernàndez stands by his reporting on the case. He said in an interview with The Intercept that the only error El Periódico made was to not initially state that the purported CIA document was an inauthentic version that the newspaper’s staff had recreated.

According to Hernàndez, he first heard about the alleged CIA notice from two sources in the Catalan government on two separate occasions in late May. (In interviews with other media, Hernàndez has said these two conversations took place in June.) The first source, he says, tipped him off to the existence of the warning, and the second, a day later, read him its contents. Both sources said the warning was from the CIA and had been sent to the Mossos raising alarm about a potential attack in Barcelona. Hernàndez says he was not physically shown the document in either meeting.

Journalists at El Periódico began investigating further, Hernàndez says, after the Catalan president, interior minister, and police chief denied the existence of a CIA warning in the days following the attack. That’s when, he says, they obtained the alleged document. Hernàndez would not discuss whether he tried to verify the document with sources in the U.S.

“This is a debate between truth and lies.”

“We had two sources,” Hernandez explains, “so either they both deceived us in the moment, and this warning was never sent and was an invention, or [the Catalan officials] deceived the public by denying the existence of the warning.”

Hernàndez’s battle seems almost personal: “If on Aug. 20, the president of the [Catalan government] hadn’t denied the existence of the warning, we wouldn’t have looked further into it,” he says. “This is a debate between truth and lies.”

The CIA and Office of the Director of National Intelligence did not respond to repeated requests for comment. Press officers from the National Counterterrorism Center refused to speak about the case.

However, in response to a request under the Freedom of Information Act, the National Counterterrorism Center did state that it had no record of any communications sent in 2017 between its office, Spanish counterterrorism police, or the Mossos.

Hernàndez argues that the communication was classified, and thus there would have been no record available under FOIA. But Sally Nicholson, FOIA chief for the Office of the Director of National Intelligence, the agency responsible for National Counterterrorism Center records, says that in the case of her agency, that is not how it works.

“If there had been communications, but they were classified, the FOIA response would have said so,” Nicholson explains. “If you have a request for something that an agency can’t admit to doing, can’t confirm or deny, you still get that answer. You’ll get ‘we can’t confirm or deny, because just by confirming or denying it would give out a classified fact.’

“If we had an exclusion for records, we would cite the exclusion in the response,” Nicholson adds. “In this case, there are no exclusions that are being cited.”

People stroll on Las Ramblas in Barcelona on April 23, 2017 on Saint George's day.<br /> Traditionally men give women roses and women give men a book to celebrate the Catalan holiday also know as "The Day of the Rose" or "The Day of the Book". / AFP PHOTO / Josep LAGO        (Photo credit should read JOSEP LAGO/AFP/Getty Images)

People stroll on Las Ramblas in Barcelona on April 23, 2017.

Photo: Josep Lago/AFP/Getty Images

Las Ramblas is like Barcelona’s Times Square — one of the city’s central streets and tourist destinations. As much now as before the attack, the street’s pedestrian walkway, which leads from the city’s central square to the Mediterranean Sea, is constantly packed with tourists, street vendors, restaurants, and the occasional artist. Even before the attack, police flanked either side of the entrance, sporting submachine guns and military-style police vans.

After the attack, police quickly found plans for what would have been a larger, more deadly atrocity: the detonation of a rental truck full of gas canisters next to the Sagrada Família, another one of Barcelona’s famous landmarks. That plan was foiled when the person modifying the gas canisters set them off prematurely in a house about 120 miles south of Barcelona.

For people on both sides of the Catalan independence movement, the Barcelona attack came to represent a grave example of the other side’s failings, explains Josep Àngel Guimerà, a journalism professor at the Autonomous University of Barcelona. Separatist press argued that there was a lack of communication between Spanish and Catalan counterterrorism police, says Guimerà. For unionists — with the help of El Periódico’s reporting — the attack came to represent the failings of the Catalan police and three top figures in the independence movement.

Guimerà notes that journalists on both sides of the movement were quick to react to the publication of the alleged CIA report. “All of the media that stand opposed to the Catalan independence movement believed Enric [Hernàndez, the director of El Periódico]. And all of those that support the movement doubted him,” says Guimerà. “There was an almost-automatic response on behalf of the media to believe the warning or not.”

Another issue is that the Spanish media doesn’t typically fact-check articles or investigations, says María Ramírez, a journalist with two decades of experience working for Spanish media. Ramírez is quick to add that individual journalists do often scrutinize and fact-check their own work, but it’s not a common practice.

“There is no newspaper in Spain that has processes of fact-checking like in the U.S.,“ Ramírez, now a journalism fellow at Harvard University, explains. “Typically [Spanish journalists], when a source passes them a document, will publish it and that’s it. It would be much more valuable to find another source and build a narrative to explain.”

“If you just publish without checking,” she adds, “you’re not doing your job for readers.”

Beyond that lies another question: If the document is indeed false, who created it?

BARCELONA, SPAIN - AUGUST 18: A police officer patrols on Las Ramblas following yesterday's terrorist attack, on August 18, 2017 in Barcelona, Spain. Thirteen people were killed and dozens injured when a van hit crowds in the Las Ramblas area of Barcelona on Thursday. Spanish police have also killed five suspected terrorists in the town of Cambrils to stop a second terrorist attack.  (Photo by Carl Court/Getty Images)

A police officer patrols on Las Ramblas on Aug. 18, 2017, following a terror attack in Barcelona.

Photo: Carl Court/Getty Images

Journalist Carlos Enrique Bayo, head of investigations at Madrid-based news organization Público, has been working on cases like these for a year and a half. In 2016, he and a colleague, Patricia López, obtained explosive recordings of conversations that took place inside the office of Spain’s then-Minister of Interior Jorge Fernández Díaz.

The publication of the conversations — in which Fernández Díaz and the former head of the Catalan anti-fraud office can be heard discussing a secret political police force — triggered a major investigation in the Spanish Congress. Congressional investigators verified that Fernández Díaz had, during his tenure as Spain’s interior minister, created a covert police unit tasked with obstructing corruption investigations into the conservative People’s Party, which has been in government in Spain since 2011. According to the congressional probe, the political police also worked to investigate Fernández Díaz’s opponents, among them people involved with the rising leftist-populist movement in Spain and the independence movement in Catalonia.

In both cases, congressional investigators found that Spanish police had leaked falsified documents to the press in order to discredit the then-interior minister’s adversaries. Bayo notes that one of those police, José Luis Olivera, now leads CITCO, the counterterrorism agency that supposedly received the purported U.S. intelligence document published by El Periódico. (CITCO did not respond to requests for comment.)

Is this a smoking gun? Bayo says no, it is not. But, he adds, it is strange that “right now, a document would appear, written in terrible English, that they say was sent by U.S. intelligence directly to the Mossos, when evidently intelligence agencies typically speak among each other.”

Guimerà, the journalism professor, agrees. While it is impossible to be certain about what happened, he says he blames a politically minded leak and journalists who don’t fact check.

“I’m sure there is a report somewhere that says generally that Las Ramblas is a target,” Guimerà remarks. But, he adds: “Out of one grain of sand, there are people here that have tried to build a mountain.”