British intelligence chiefs at MI5 ignored warnings from the FBI in January that Manchester bomber Salman Abedi was planning an attack in Britain.
According to a security officer, the FBI warned MI5 that Abedi was connected to an ISIS cell plotting to strike a political target in the UK at some point in 2017.
The FBI’s information came from an investigation into Abedi and his links to known terrorist groups in Libya. He had been placed on a terror watch list by the US security services as a result.
Daily Mail reports: The shocking claim piles further pressure on MI5 to reveal when and how it became aware of Abedi, and why UK spies decided he did not pose a significant threat to British security.
The source told The Mail on Sunday: ‘In early 2017 the FBI told MI5 that Abedi belonged to a North African terror gang based in Manchester, which was looking for a political target in this country.
‘The information came from the interception of his communications by US federal agents, who had been investigating Abedi since the middle of 2016, and from information unearthed in Libya, where his family was linked to terrorist groups.
‘Following this US tip-off, Abedi and other members of the gang were scrutinised by MI5. It was thought at the time that Abedi was planning to assassinate a political figure.
‘But nothing came of this investigation and, tragically, he slipped down the pecking order of targets.’
Last night, The Mail on Sunday put the claim to the FBI but a bureau spokesman declined to comment, while UK security sources did not confirm the specific claim about the tip-off.