MI6 conspired with France to help Gaddafi's son

Saif al-Islam leaves the High Court in London in 2002 after winning a libel case against The Sunday Telegraph. (REX)

British intelligence and Scotland Yard were involved in an operation to protect Saif al-Islam, the son of Muammar Gaddafi, from an Islamist plot to assassinate him on British soil, secret files discovered by i have revealed. British intelligence services suspected that the plot was linked to Qatar, the West's foremost Arab ally in the fight to oust Gadaffi.

MI6 and the SAS are now involved in the hunt for Saif and other members of the Gaddafi family still at large in the endgame of the Libyan civil war. The dictator's son has been condemned by the Prime Minister, David Cameron, and Nicolas Sarkozy, the French president, for his part in the brutal crackdown that followed the February uprising.

But MI6 once urgently contacted its French counterparts after Libyan authorities reported that terrorists linked to Qatar were planning to attack the dictator's son from Paris. French officials told their UK counterparts at the time that "the Qatari interior minister was a known Islamist extremist sympathiser".

No evidence was presented to back up the charge. But the same minister was once believed by US agents to have links to al-Qa'ida. A Los Angeles Times report of March 2003 accused Sheikh Abdullah bin Khalid al-Thani of sheltering terrorists. Richard Clarke, a former White House counter-terrorism director, said that his role as security chief in Qatar presented a serious danger to US forces posted there. Qatari officials did not comment on the claims.

Qatar is now one of the largest funders of the Libyans who overthrew Muammar Gaddafi. The Gulf state is also a conduit, it is claimed, for supplying Western arms to the rebels.

Details of Libya's bid to seek help from the UK to save the life of the dictator's son came in a letter from a senior MI6 official to an official in the regime's international relations department. It was among documents related to Saif al-Islam found at the Foreign Ministry in Tripoli and in the office of Moussa Koussa, the country's former foreign minister and spymaster who defected in the early days of the revolution.

The letter of 20 January 2004 read: "We have passed the details regarding the threat to Saif to our French counterparts.

"They have advised us that they do not have any traces on the individuals in the report... They commented that the Qatari interior minister was known to be an Islamist extremist sympathiser. They are carrying on with their investigation."