Abu Hamza: I was tipped off about 9/11

Abu Hamza led London's Finsbury Park Mosque, reportedly attended by September 11 conspirator Zacarias Moussaoui. Reuters

Abu Hamza, Britain's most notorious hate preacher, says he was told four days before the 9/11 attacks that "something very big will happen very soon", according to The Sunday Times.

He took the call, delivered by the cleric’s militant contacts in Afghanistan, to be about an impending terrorist strike on America and believes the phone at his west London home was being “tapped” by police at the time.

If true, the claim raises questions about whether British authorities were aware of the warning and failed to pass it on to their American counterparts before the terrorist attack which involved hijacked planes being flown into the World Trade Center in New York and the Pentagon in September 2001.

American court papers, seen by the British paper, detailed the phone call and revealed that Abu Hamza acted as an agent for the British intelligence agency MI5 under the code name “Damson Berry”.

In a 124-page handwritten submission, Abu Hamza writes: “What made pro-war governments and intelligence [agencies on] both sides of the Atlantic more furious about the defendant [Abu Hamza is] that defendant received a call from Afghanistan on Friday, September 7, 2001, from 2 of his old neighbours in his Pakistan time (1991-93), saying ‘something very big will happen very soon’.”

Abu Hamza denies the call came from Al Qaeda figures.

The former imam of Finsbury Park mosque in north London is appealing against his conviction for terrorist offences and his "inhuman" incarceration at an American"supermax" prison.