MADRID - A Belgian policeman told a Catalan colleague in 2016 that the imam believed to be the instigator of last week's attack in Barcelona was suspicious, but no information was found back then to link him to Islamist militancy, a source told Reuters.
Police in the northeast Spanish region of Catalonia are coming under growing criticism over the van attack that killed 13 people. Two others were killed during the driver's getaway and in a separate attack further down the coast.
Several Spanish media accused Catalan police on Thursday of failing to properly investigate the Moroccan imam, Abdelbaki Es Satty. Meanwhile a wider blame game is being played out between central authorities in Madrid and officials in Catalonia, whose leaders are pushing for independence from Spain.
The tip-off about the imam was made informally between two police officials from Belgium and Catalonia who knew each other, a source in Catalonia's regional government said.
"The communication between the two policemen was not official. They knew each other because they had met in a police seminar," the source said, on condition of anonymity.
Police records, however, had turned up nothing on the cleric. "The documents show that we had no information about the imam," the source said, adding that the only official communication channels of the Catalan police, the Mossos d'Esquadra, with police in other countries were through Spain's central government.
The Catalan regional government and Spain's central government declined to comment.
It remains unclear whether Catalan police made their own attempts to follow up on the lead.
Es Satty spent around three months in the Belgian town of Vilvoorde, a known center of Islamist radicalism, between January and March last year.
He later went to Catalonia as the imam of the small town of Ripoll, where he is suspected of having recruited and radicalized most of the group which carried last week's attacks.
Hans Bonte, mayor of Vilvoorde, said last week that Es Satty had been "intensely screened" by Belgian police at the time, and he had told Spanish police by email of his whereabouts.
El Pais newspaper quoted Bonte on Thursday as saying he had received a reply from police in Barcelona on March 8 last year. "They said the imam had no links to radical groups," he said.
Sources close to the investigation told Reuters earlier this week the regional Catalan force may have missed an opportunity to uncover the plot because of procedural errors and a lack of communication among investigators.The errors and miscommunication centered around a major blast on Aug. 16, the eve of the attack, at a house where it was later discovered that suspected Islamist militants were making explosives, the sources said.