The judge, Col. James Pohl, gave Spc. Jeremy C. Sivits, the maximum sentence: confinement for one year, a reduction in rank to private and a bad-conduct discharge from the Army.

The 24-year-old military police reservist wept at his court martial and apologised to his victims, saying he does not want to be thrown out of the US army.

"I'd like to apologize to the Iraqi people and those detainees," said Sivits. "I should have protected those detainees, not taken the photos."

He told how fellow US soldiers sexually humiliated naked Iraqi detainees and punched one so hard he needed treatment.

He also wanted to apologise to the army and his family. "I've let everybody down. That's not me."

Sivits, who pleaded guilty to four abuse charges as part of a pre-trial plea agreement, told the court that fellow members of his unit gravely abused prisoners and that he knew it was wrong, but participated anyway.

Lawyers for some of the other soldiers have already dismissed Sivits' accusations as fabrication.

Most of the other soldiers maintain they were following orders, while Sivits says these were all individual actions, a stance the administration is keen to push.

Earlier yesterday, Staff Sgt Frederick, Sgt Davis and Spc Graner, who are also implicated in the abuse scandal, appeared in court.

They face more serious charges than Sivits, including physical assaults on prisoners.

They deferred entering pleas and were ordered to appear in court again on 21 June.