David Miliband's statement to the Commons drew heavy criticism of the government's previous stance on rendition flights from opposition figures and human rights groups.

Former Liberal Democrat leader Sir Menzies Campbell, who tabled a parliamentary question on the issue in 2005, said the revelation was a "gross embarrassment" for the government.

"This will give rise to continued speculation that there have been other instances of rendition through Britain itself or its territories," Campbell told guardian.co.uk. "We have not heard the last of this issue."

Civil rights group Reprieve demanded a full public inquiry into rendition flights.

"For about four or five years the British government has been denying that any detainees have been held or transferred through Diego Garcia, despite mounting evidence to the contrary, and relying on bland US assurances that this hasn't happened," said Chloe Davis, a Reprieve researcher.

"We are glad the government are coming clean. We hope this new information is sufficient grounds for a full public inquiry into who these men were, what happened to them after they left Diego Garcia and what authorisations enabled this to happen," she said.

Amnesty International also said the government's admission had prompted further questions.

"Can the government now assure the public that other planes involved in the secret US movement of prisoners to places like Guantanamo Bay have not flown through UK air space or that of UK overseas territories?" Amnesty's UK director, Kate Allen, asked in a statement.

"And, can the government ensure that 'rendition' planes will not be using UK airspace or facilities in the future? It is not enough for the government simply to accept US assurances on correct behaviour in the 'war on terror' - we should retain our own integrity and act accordingly."

Mike McDonough