Fusilier Gary Bartlam was also involved in a “disgraceful” episode in which another serviceman held a Minimi machinegun to the heads of three civilian prisoners kneeling with their faces against the ground.

Although he claimed to be simply a bystander who took the pictures as souvenirs, he was really the “prime mover” in the mistreatment of detainees at Camp Bread Basket, the aid centre near Basra.

The hearing was told that the fusilier, a “nutter” with a liking for violence, faced sexual incitement and assault charges there and at two other camps in Iraq before the launch of Operation Ali Baba, which was designed to capture looters. To one prisoner he assaulted at Camp Apache, he said: “If I had my way you would be dead.”

But he made a deal with army prosecutors in which four serious charges were dropped in return for his giving evidence against three of his senior colleagues in Milan Platoon of The Royal Regiment of Fusiliers who took part in the operation on May 15, 2003.

The deal meant that he faced a maximum of two years in prison instead of a ten-year tariff. It also ensured that evidence he gave the court martial would “deliver the scalp to the prosecution” of Corporal Daniel Kenyon, the platoon commander, it was alleged.

At the hearing in Osnabrück, Germany, Corporal Kenyon, 33, Lance Corporal Mark Cooley, 25, and Lance Corporal Darren Larkin, 30, deny abusing, assaulting and humiliating prisoners. Fusilier Bartlam, 20, who was originally due to stand trial alongside them, was convicted at a court martial earlier this month of three charges of taking photographs wilfully to encourage others to continue the abuse. The pictures showed naked prisoners in simulated sexual positions and suspended in a net from a forklift truck. He had taken his film to a shop in Tamworth, Staffordshire, where an assistant decided to alert civilian police.

On the eighth day of the hearing, Joseph Giret, counsel for Corporal Kenyon, told Fusilier Bartlam: “You are a thoroughly dishonest person and your conduct on that day and other days was demonstrably disgraceful, and there was evidence to suggest that.”

Accused of inciting other servicemen in the mistreatment of the Iraqis, Fusilier Bartlam said: “I am guilty of taking the photos and the seriousness of that, that’s all I’m guilty of.”

When it was suggested that he was a “nutter”, he added: “I am not. If I was a nutter I would be in a mental institution and I am not.”

He was referred by Mr Giret to an interview he had had in 2003 with the Royal Military Police in which he had absolved Corporal Kenyon.

He had told officers that the corporal had stepped in during the abuse of prisoners, saying, “that’s it lads, f****** end it”, or “that’s enough. Stop it. Stop doing it.” But in a statement on January 10 this year he had failed to mention his platoon commander’s words. Yesterday he said: “Yes, but now, having had time, I can’t be sure if he did say that.”

Mr Giret suggested: “You have put Corporal Kenyon into the frame as part of your plan to save your skin.”

The hearing continues today.

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