LONDON — One of the three attackers who murdered revellers in central London last Saturday had been reported to the anti-terror police on at least two occasions, British media reported.

A former friend of the terrorist, who was shot dead by police along with two accomplices, claimed he had been radicalised while watching YouTube videos and said he had contacted the authorities after becoming concerned over his friend’s extremist views.

A neighbour also said she had contacted police in Barking, east London, after the suspect tried to convert her children to Islam and radicalise them.

The man was known to locals in Barking as Abu Zeitoun, but is understood to have a different birth name. The former friend claimed he contacted police after comments the man made about other previous attacks.

But he said the authorities had failed to act and take action despite evidence of increasingly extremist views. The friend told the BBC’s Asian Network that the terrorist, known as Abu or Abs, had been radicalised watching videos of the infamous American hate preacher Ahmad Musa Jibril.

He said: “We spoke about a particular attack that happened and like most radicals he had a justification for anything and everything. That day I realised I needed to contact the authorities.”

He added: “He used to listen to a lot of Musa Jibril. I have heard some of this stuff and its very radical. I am surprised this stuff is still on YouTube and is easily accessible. I phoned the anti-terror hotline. I spoke to the gentleman. I told him about our conversation and why I think he was radicalised.”

However, he said he was not arrested and was allowed to keep his passport. “I did my bit, I know a lot of other people did their bit, but the authorities did not do their bit,” the friend said.

Ms Erica Gasparri, an Italian mother of three who lived close to him, claimed she had reported him to Barking police two years ago, after he began “brainwashing” her children at a local park. She said she had confronted him after her two children came home and said: “Mummy I want to become a Muslim.” She said the police had told her the information had been passed to Scotland Yard but she had heard nothing more.

Ms Gasparri said: “He was trying to radicalise the children, he would go down to the park and talk to them about Islam. He also came to the houses and gave the kids money and sweets during Ramadan.”

Anti-terror police raided the block of flats on King’s Road in Barking, where Abu was believed to have lived with his wife and two children. Many locals described him as “polite and normal” and were shocked that he could be a terrorist. Residents said he was a keen football fan who also enjoyed body-building at a local gym. But it also emerged that he was thrown out of his local mosque two years ago after clashing with the imam about politics.

The attacker was wearing his Arsenal away shirt when he and two others went on the rampage at London Bridge, leaving seven dead and almost 50 injured. All three were shot dead by armed police in Borough Market, eight minutes after launching the attack.

It has also emerged that Abu had appeared in a jihadi documentary on Channel 4 about British extremists called The Jihadis Next Door last year, and was filmed at events attended by two notorious Islamic preachers.

A relative also told how he had previously tried to go to Syria to fight but had been talked out of it by his family as his wife was pregnant at the time. Neighbours said he had previously worked for Transport for London and a branch of fast food chain KFC.

Another attacker was carrying an ID card issued in Ireland and he was shot dead, security sources in the Republic have confirmed. Police chiefs in Dublin said they were liaising with counterparts in the United Kingdom amid reports that he had Irish papers.

“An Garda Siochana (the Irish police) is providing every assistance to our colleagues in the London Metropolitan Police in relation to the terror attack in London,” a spokesman said. “We will process all requests from the UK authorities in relation to inquiries into individuals, identities or any other matter.” THE DAILY TELEGRAPH