A close friend of former weapons inspector David Kelly wrote to the Attorney General calling for an independent review into his death, according to reports.

US Air Force officer Mai Pedersen's intervention came after Attorney General Dominic Grieve indicated that he was "concerned" about the Kelly case and interested in exploring how to take the matter forward.

No inquest was ever completed into the death of Dr Kelly in 2003, just days after he was identified as the source of stories questioning then prime minister Tony Blair's case for war in Iraq.

But the Hutton Inquiry into his death found that he killed himself by swallowing 29 painkillers and slitting his left wrist.

Ms Pedersen, who worked with Dr Kelly in Iraq in the 1990s and remained a close friend, challenged this finding in 2008, revealing that he had an injury to his right elbow which made it difficult for him to cut with a knife.

Shortly before his death, he was unable to cut a steak when having dinner with her, she said. And she said that he had a dislike for pills which made it unlikely he would have chosen that method of ending his life.

According to the Daily Mail, she wrote to Mr Grieve, saying: "We understand you have indicated a willingness to consider possibly re-opening the investigation into the continuing controversy into the death of Dr Kelly.

"Given the absence of any coroner's inquest and the perpetual secrecy surrounding the post-mortem examination, it is painfully obvious that this matter continues to cry out for a formal, independent and complete review. Ms Pederson fully supports and adds her voice to such an effort. The passage of time (does) not diminish either the public's interest or the Government's responsibility to ascertain the full truth, whatever that might be."

The Attorney General's office was unable to confirm whether it had received a letter from Ms Pedersen. A spokesman repeated an earlier statement, saying: "The Attorney remains concerned about this issue and is keen to explore how the matter might be taken forward with ministerial colleagues."

Mr Grieve has no power to order a new public inquiry, but could make an application to a coroner for an inquest if there is evidence to support it.