London, Aug 27 : A terror suspect held over threats to kill British Prime Minister Gordon Brown has allegedly had contact with Osama Bin Laden’s deputy, Ayman Al-Zawahiri.

He is one of four men being quizzed by police over messages on an extremist website calling for the Prime Minister to be assassinated.

Cops are thought to be probing an Internet message he allegedly sent to awahiri, the al-Qaeda No. 2 who dreamt up the 9/11 atrocities.

One chilling section read: “Is the British Muslim allowed to kill British civilians, whether they are nonbelievers or Muslims who support the war against Afghanistan, Iraq and others?”

Another asked Al-Zawahiri if jihad was an “obligation” for Muslims in Britain, The Sun reported.

A man calling himself Sheikh Umar Rabie, who bragged he was al-Qaeda’s leader in the UK, sent the notes.

A source close to the investigation said last night: “The links between those arrested and Umar Rabie are central to this. Any attempted contact between Rabie and known extremists is significant.”

The threat to Brown, posted in January, demanded the release of prisoners including hook-handed cleric Abu Hamza.

All four being held are from Blackburn, Lancs.

Three of them - aged 21, 22 and 23 - were arrested on August 14.

Two were held as they tried to board a flight to Finland at Manchester airport, and the third was seized in Accrington.

A fourth man, a white Muslim aged 24, was arrested in a dawn swoop on Tuesday. He works in a Blackburn chemist’s shop and is known as Muhammad Ali.

The message to Al-Zawahiri was written in Arabic. US experts later translated it into English before being passed to British cops. (ANI)