Ali Fadhil, who two months ago won the Foreign Press Association young journalist of the year award, was hooded and taken for questioning. He was released hours later.

Dr Fadhil is working with Guardian Films on an investigation for Channel 4's Dispatches programme into claims that tens of millions of dollars worth of Iraqi funds held by the Americans and British have been misused or misappropriated.

The troops told Dr Fadhil that they were looking for an Iraqi insurgent and seized video tapes he had shot for the programme. These have not yet been returned.

The director of the film, Callum Macrae, said yesterday: "The timing and nature of this raid is extremely disturbing. It is only a few days since we first approached the US authorities and told them Ali was doing this investigation, and asked them then to grant him an interview about our findings.

"We need a convincing assurance from the American authorities that this terrifying experience was not harassment and a crude attempt to discourage Ali's investigation."

Dr Fadhil was asleep with his wife, their three-year-old daughter, Sarah, and seven-month-old son, Adam, when the troops forced their way in.

"They fired into the bedroom where we were sleeping, then three soldiers came in. They rolled me on to the floor and tied my hands. When I tried to ask them what they were looking for they just told me to shut up," he said.