The Central Intelligence Agency (CIA) has worked closely with Libyan dictator Muammar Gadhafi in imprisoning terrorists suspects, according to documents found in Tripoli by Human Rights Watch.

The documents reveal that the CIA worked with Gadhafi's intelligence agencies in capturing Abdel-Hakim Belhaj, the former leader of the Libyan Islamic Fighting Group that has links to al-Qaida. The CIA also gave Gadhafi information on Libyan antagonists in Britain.

Human Rights Watch emergencies director Peter Bouckaert told the Guardian that the documents represent "a very dark chapter in American intelligence history, and it remains a stain on the record of the American intelligence services that they cooperated with these very abusive intelligence services."

Britain's security services also appear in contact with the Libyan government, with talks between London and Tripoli before then Prime Minister Tony Blair's meeting with Gadhafi in a desert tent.