Intercepted communications showed former ISI chief Mahmoud Ahmad and his colleagues stationed in Washington were in constant contact with attaches in the Turkish embassy, according to The Sunday Times.

Sibel Edmonds, a 37-year-old former Turkish language translator for the FBI, listened into hundreds of sensitive intercepted conversations while based at the agency’s Washington field office, it said.

She approached the newspaper last month after reading about an al-Qaeda terrorist who had revealed his role in training some of the 9/11 hijackers while he was in Turkey.

Edmonds described how foreign intelligence agents had enlisted the support of US officials to acquire a network of moles in sensitive military and nuclear institutions.

According to Edmonds, she heard evidence that one well-known senior official in the US State Department was being paid by Turkish agents in Washington who were selling the information on to black market buyers, including Pakistan.

Intelligence analysts said that members of the ISI were close to al-Qaeda before and after the 9/11 attacks on the US. Ahmad was accused of sanctioning a 100,000 dollar wire payment to Mohammed Atta, one of the 9/11 hijackers, immediately before the attacks, the report said.

The newspaper claimed that it knew the name of the official, who has held a series of top government posts, but he strongly denies the claims.