Tariq Mahmud, 30, from Birmingham was arrested in Pakistan as part of an international operation orchestrated by American, British and Pakistani intelligence officials.
Aljazeera.net has learnt that Mahmud is being detained by the American military in Bagram airbase, Afghanistan.
Sources have told Aljazeera.net that on the same day Mahmud was arrested another British national was detained by Pakistani authorities and questioned. The man, who has not been named, was later released and has since returned to the UK.
Aljazeera.net contacted US central command to find out if they could shed any light on the whereabouts of Tariq Mahmud.
''All detainees in coalition custody are treated humanely''
Major David Farlow,
US Central Command
Major David Farlow told Aljazeera.net that '' as a matter of policy and for operational security reasons we do not comment on the status of any individuals whom Coalition Forces are detaining. All detainees in coalition custody are treated humanely".
When pressed if this meant that the Americans were holding Mahmud, Major Farlow replied: ''No."
The British Foreign Office has told Aljazeera.net Mahmud is being held in Pakistan and is being questioned by Pakistani officials.
Prisoners prepare for prayer at
the US naval base
''We are pressing the Pakistani's to allow our consulate to make contact with this individual. We have sent the Pakistani's a photocopy of Mr Mahmud's passport and some photographs to assist them with their inquiries,'' said a Foreign Office spokesperson.
The spokesperson went on to say that they had no information to suggest that Mahmud was being detained by the Americans.
The official also confirmed that a second British man was arrested and questioned by the Pakistanis at the same time as Mahmud's arrest, but he has since been released and is back in the UK.
A campaigner working on behalf of the British detainees in Guantanamo says that Tariq Mahmud could have been picked up by the Americans to gather evidence against another Birmingham man, Mozzam Begg whose arrest mirrors that of Mahmud's.
Begg was held in Bagram for a year before being taken to Guantanamo Bay where he has been held for over a year without charge.
''Mozzam Begg is going to be put on trial by the Americans very soon. They don't have any evidence against him, my guess is that they are hoping that Mahmud can offer them some new information'' said a member of Prisoner of West, a group campaigning to release British prisoners.
Mozzam Begg's father, Azmat Begg told Aljazeera.net that as far as he was concerned his son and Mahmud had never been in contact, but since both men are from Birmingham there was a possibility that they may have known one another.