An Iranian-born Territorial Army corporal who spied for Tehran while serving as an interpreter to a British commander was sentenced to ten years in prison at the Old Bailey yesterday.

Corporal Daniel James, who worked for General Sir David Richards when he commanded Nato troops in Afghanistan in 2006, was convicted on November 5 of communicating with a military attaché at the Iranian Embassy in Kabul, the Afghan capital. The sentence could have been up to 14 years.

Mr Justice Roderick Evans, passing sentence, said: “The gravest part of your offending, and what made this case unique, was that you engaged in this activity when you were actually serving in a war zone.”

Mark Dennis, QC, for the prosecution, had told the trial that James’s treachery could have cost the lives of his fellow British soldiers, because there was evidence that the Iranians had supported military action against troops in Helmand province in southern Afghanistan.

Mr Justice Evans said: “There has to be a sentence which is a deterrent, so that people know that if they engage in this kind of activity it will be met by heavy sentences from the courts.” He added: “You were in a theatre of war. Your colleagues and companions were at daily risk of being injured or killed.”

The judge said that when James was in the relationship with Iran, he believed that the Iranians were supporting the insurgency in Iraq. He added, however, that James was “a ripe target” for the Iranians because of his dual Iranian-British citizenship, his “narcissistic” personality and his disenchantment with the Army. He had complained that he had been passed over for promotion to sergeant.

The judge said he agreed with Colin Nicholls, QC, for the defence, that, with his background, James should never have been appointed to the sensitive post of interpreter to General Richards. The court was told that there were few qualified military interpreters available, and James, 45, a salsa dancer and body-builder, spoke Dari, the local language, and Farsi.

He was arrested in December 2006 after investigators discovered that he had sent e-mails, some of them in code, to Colonel Mohammad Hossein Heydari at the Iranian Embassy.

James was charged under Section 1 of the Official Secrets Act. The judge accepted that James had been contacted by the Iranians, not the other way around. However, he said that James had a “grossly inflated view” of his own importance and ability.

The judge also conceded that there had been “no known damage” to Britain or to Nato or to allied operations in Afghanistan. “[But] the potential for serious harm, had this relationship between you and the Iranian authorities developed, was immense,” he said.

James will serve half the ten-year term in custody, minus the 709 days he has been on remand. He will be out of prison in three years.

Times Recommends

• The bright side of this winter rain
• Story behind the picture: Snow Leopard, 2008
• Times Charity Appeal: The Place2Be