The man accused of masterminding the September 11 attacks on New York and Washington also planned to crash hijacked airliners into Heathrow, documents released by the US government claim.
Khalid Sheikh Mohammed conceived a plot to hit Heathrow after the attacks on the US five years ago, America's Office of the Director of National Intelligence (Odni) said.
Ramzi Bin al-Shibh, described as a "key facilitator" in 9/11, was said to have been a "lead operative" in Mr Mohammed's Heathrow plan, which the US said was disrupted in 2003.
The details emerged in profiles of 14 terror suspects, including Mr Mohammed and Mr Bin al-Shibh, who, the US announced yesterday, had been transferred from secret CIA prisons around the world to Guantanamo Bay in Cuba.
During a speech about the CIA programme, President George Bush said information from those held had "helped stop a plot to hijack passenger planes and fly them into Heathrow or Canary Wharf in London".
Mr Bin al-Shibh was said to have been a would-be 9/11 hijacker who fled Afghanistan after the overthrow of the Taliban in late 2001 and headed to Karachi. There, he and Mr Mohammed worked on "follow-on plots against the West, particularly the Heathrow plot", the US document said. He was captured in 2002.
The statement continued: "He was tasked by Mohammed to recruit operatives in Saudi Arabia for an attack on Heathrow airport, and as of his capture, Bin al-Shibh had identified four operatives for the operation."
In another document, summarising the so-called High Value Terrorist Detainee Programme, Odni said the "Heathrow airport plot" had been disrupted in 2003 on the basis of information that came from detainees.
"In 2003 the US and several partners - acting on information from several detainees - disrupted a plot to attack Heathrow airport using hijacked commercial airliners," it said.
"Mohammed and his network were behind the planning for this attack."
The US government gave similar information on an alleged Heathrow attack last autumn, but merely said then that the planning had been by "a major 9/11 operational figure".
Scotland Yard said it was "not prepared to discuss" Mr Bush's comments.Reuse content