British Defense Minister Philip Hammond has confirmed that up to 90 Afghans are being held by British forces in a detention facility in southern Afghanistan.
Hammond said their detention is legal.
He said the detainees will be transferred to Afghan authorities.
Earlier, the BBC reported that British forces have been "unlawfully" holding the men in Camp Bastion, the largest British military base in Afghanistan.
Afghan Defense Ministry spokesman Zahir Azimi said their detention was "against Afghan law." Azimi said the detainees should be handed over to Afghan authorities.
Lawyers representing eight of the men told the BBC their clients have been secretly held for up to 14 months without being charged.
The suspected insurgents, including teenagers, were reportedly arrested during British soldiers’ raids in Afghan villages.
British forces are allowed to hold detainees for longer than 96 hours without charges only in exceptional circumstances.
Britain's Defense Ministry has previously said that the NATO-led coalition neither has the power nor the facilities to intern detainees in Afghanistan.
Based on reporting by the BBC and dpa