Amnesty International has called on the UK government to take up the case of Bradley Manning, the soldier accused of passing US military secrets to WikiLeaks, on the grounds that he is a British citizen.
Human rights watchdog Amnesty, which recently labelled Manning's treatment 'inhumane', is urging UK authorities to ensure that Manning's conditions are brought into line with international standards.
The conditions under which Manning is being detained at the US army brig in Quantico, Virginia, have been condemned as 'torture'.
Manning was born in Oklahoma in 1987 to an American father and a Welsh mother. After his father left home when Manning was 13, he came to Wales his mother, where he attended school and took his GCSEs in Haverfordwest before returning to the US to enlist.
Under the British Nationality Act of 1981, anyone born outside the UK after 1 January 1983 whose mother is a UK citizen by birth, is regarded as 'British by descent'.
"Nationality is like an elastic band: it stretches to one generation born outside the UK to a British parent. And that makes Bradley Manning British," Alison Harvey, head of the Immigration Law Practitioners' Association in London, told the UK's Guardian newspaper.
Amnesty's UK director, Kate Allen, says Manning's British nationality should prompt the UK's government to intervene over his detention.
"His Welsh parentage means the UK government should demand his 'maximum custody' status does not impair his ability to defend himself," she told the Guardian. "We would also like to see Foreign Office officials visiting him just as they would any other British person detained overseas and potentially facing trial on very serious charges."
The British embassy in Washington says it has so far received no requests to visit Manning in jail. "It hasn't crossed our path yet," an official said.
Manning has been held in solitary confinement by the US military since his arrest more than seven months ago. Locked in his cell for 23 hours a day, he is denied even a pillow or sheets for his bed.
Authorities at the Quantico brig came under fire earlier this month when it was reported that the prison's Commander, James Averhart, had contravened regulations by placing Manning on suicide watch.