MI6 believed it was close to finding the al-Qaida leader in Afghanistan in 1998, and again the next year. The plan was for MI6 to hand the CIA vital information about Bin Laden. Ministers including Robin Cook, the then foreign secretary, gave their approval on condition that the CIA gave assurances he would be treated humanely. The plot is revealed in a 75-page report by parliament's intelligence and security committee on rendition, the practice of flying detainees to places where they may be tortured.

The report criticises the Bush administration's approval of practices which would be illegal if carried out by British agents. It shows that in 1998, the year Bin Laden was indicted in the US, Britain insisted that the policy of treating prisoners humanely should include him. But the CIA never gave the assurances.

"In 1998, SIS [MI6] believed that it might be able to obtain actionable intelligence that might enable the CIA to capture Osama bin Laden," the committee says in its report. It adds: "Given that this might have resulted in him being rendered from Afghanistan to the US, SIS sought ministerial approval. This was given provided that the CIA gave assurances regarding humane treatment." British intelligence made a similar request in 1999, and obtained the same response from Whitehall, but in the event MI6 did not provide the information.

But 1998 and 1999 were not the only times Britain had Bin Laden in its sights. In January 1996 the Home Office wrote to him when he was in Sudan. The letter, seen by the Guardian, advised him that Michael Howard, then home secretary, had "given his personal direction that you be excluded from the United Kingdom on the grounds that your presence...would not be conducive to the public good."

· The following correction was printed in the Guardian's Corrections and clarifications column, Thursday August 2 2007. In the article above regarding a report on rendition by parliament's intelligence and security committee we said correctly that it had criticised the Bush administration's approval of practices that would be illegal if carried out by British agents. As a result of cutting during the editorial process, most of the article concerned events from 1996-99. This might have given readers the impression that we thought George Bush was president during that time.