RELATIVES of a former Huddersfield University student held at Guantanamo Bay lost their bid to force the Foreign Secretary to seek his release.
The family of Omar Deghayes, 37, went to court after condemning the Government for not putting enough pressure on the United States.
Ministers argued that although Mr Deghayes was a British resident he was not an actual citizen.
Three judges at the Appeal Court in London ruled yesterday that they could not interfere with the Foreign Office decision that there was no duty to act.
Two other men held at the US base on Cuba were also a involved.
Mr Deghayes - originally from Libya - was on a law practice course at Huddersfield University in 1998 before becoming a student in Brighton, East Sussex.
He was arrested in Pakistan in 2002 and accused of committing terrorist acts against the US.
He fled Libya for the UK in the 1980s after his father was assassinated. He applied for British citizenship.
Relatives say Mr Deghayes has no links to terrorism.
His sister, Amani Deghayes, said: "Instead of standing up for my brother the Government is pretending he's nothing to do with them, an illogical and inhumane attitude.
"Omar has already been held for over four years without charge or trial.
"We've always said that we're not looking for special favours, just for his fundamental human rights to be respected," she added.
Amnesty International said it was disappointed at the ruling.
Nicola Duckworth, the charity's Europe and Central Asia director, said: "The Appeal Court has missed an opportunity to send a clear message that the government must fulfil its responsibilities towards all Guantanamo detainees, regardless of whether they are UK citizens or residents."