British soldiers have held Afghan detainees captive without trial or access to legal help for up to 14 months, it has emerged.
The Ministry of Defence has confirmed around 90 Afghans are now being held at a detention facility at British forces' base at Camp Bastion.
Eight of them are being helped by British lawyers to bring their cases to court, arguing that their imprisonment is effectively unlawful detention.
"The UK could have trained the Afghan authorities to detain people lawfully with proper standards, making sure they're treating them humanely," lawyer Phil Shiner told the Today programme.
"They could then have monitored that facility to make sure the Afghans were obeying the law.
"Instead they've chosen to go down a route which is deeply constitutional. Flagrant breaches of common law and international law - that's not the answer."
Defence secretary Philip Hammond denied Shiner's claim that parliament had not been informed, insisting the Commons had been notified of the temporary facility.
He said usually only around 20 Afghans were being held at any one time, but blamed British lawyers for raising question-marks about the way the detainees would be treated by the Afghan authorities.
Hammond confirmed he had himself ordered the suspension of prisoner transfers after concerns were raised about a specific Afghan facility last November.
"We would like nothing more to be handing these people to the Afghan authorities," he complained to the same programme.
"But... last year his firm started proceedings against the department precisely to prevent us handing them over to the Afghan authorities precisely because of concerns about the treatment of prisoners in the system.
"These people are being held pending transfer to the Afghan national security system. Within that system they would have access to Afghan lawyers."
Transfers are expected to resume "within days".