"There is nothing wrong with trying minors for crimes, if they have committed crimes," Clive Stafford Smith, a legal director of the London-based legal rights group Reprieve and lawyer for a number of detainees, told the daily.

"The problem is when you either hold minors without trial in shocking conditions, or try them before a military commission that, in the words of a prosecutor who refused to take part, is rigged," he said.

The group estimates that more than 60 detainees were boys under 18 when they were captured.

They include at least 10 detainees still held at the infamous detention center who were 14 or 15 when they were seized.

The US admits only three young Afghans, one aged 13, were ever treated as children.

"We would take a very, very dim view if it transpires that there were actually minors there," a British government official told the daily.

Click to read the Independent's report in full