The home secretary has lost an 11th hour legal bid to prevent the release of a terrorist suspect.

David Blunkett was told by the Court of Appeal on Thursday that one of the 13 men being held under anti-terror legislation at Belmarsh prison should be freed.

The man, known as M for legal reasons, was accused of giving support to groups linked with al Qaeda.

He had won an appeal against indefinite detention last week at the Special Immigration Appeals Commission but Blunkett has argued he was right to certify him as a suspected terrorist.

Ben Emmerson QC, representing M, said some of the evidence against his client was "clearly misleading".

The lord chief justice, Lord Woolf, decided that if the Special Immigration Appeals Commission rules that the detention is unlawful, then the detainee has to be released.

Human rights campaigners said the case should never had reached the courts.

"This challenge by the home secretary - tantamount to appealing against an acquittal verdict - should never have happened in the first place," said Amnesty International UK director Kate Allen.

"The verdict highlights the very real dangers of legislation that allows the UK government to detain people without charge or trial on the basis of secret 'evidence' that would not stand up in a court of law."