A row has broken out over leaked footage showing US air force pilots attacking a British convoy in Iraq leading to the death of Lance Corporal Matty Hull.

The Sun newspaper obtained the 2003 friendly fire footage after the inquest into the incident was refused permission to show the cockpit film of the attack in court.

The Ministry of Defence had resisted its release on the grounds that it was classified in America as secret.

But foreign secretary Margaret Beckett reacted by saying there should now be a "full inquest" into the death and that Britain is "working with the US" to get all the information.

Shadow defence secretary Liam Fox said the affair had showed up weaknesses in the inquest system.

"As far as the public is concerned about the information sharing, what's emerging is that there are no very clear rules surrounding that and that needs to be sorted out," the Conservative spokesman told BBC News 24.

"As far as our inquests are concerned I'm afraid that it is not working quickly enough, there are far too many delays for the families involved and it leads to a lot of suffering.

Liberal Democrat leader Sir Menzies Campbell claimed the fact that the US authorities were not fully co-operating with the inquest showed relations between London and Washington were distorted.

Meanwhile constitutional affairs minister Harriet Harman, a contender for Labour's deputy leadership, said all information about Hull's death should be made available.

"The position we have always taken, and convey in the strongest possible terms in meetings and letters to the American authorities via the US embassy deputy chief of mission David Johnson, is that they should comply with all requests from the coroner," she said.

"The difficulty is that the coroner does not have any legal powers of compulsion for anything that is outside this jurisdiction.

"Therefore, it has been a question of making it clear to them how important I thought it was that they comply with the coroner's requests.

"The importance of the inquest is twofold: firstly, so that when there is a sudden, unexplained or violent death the public can know what has actually happened, but even more importantly, so that those whose relatives have died can find out what happened."

Asked about whether it was right that the video had been leaked to the Sun, she said: "I have always taken the view that what is important is that the families get all the information available to help them understand what happened.

"People do understand that, in armed conflict situations, terrible accidents do sometimes happen, but what I think people do not understand or accept is the notion that the truth should not be revealed."