Princess Diana was not pregnant when she died, a former royal coroner says, apparently ruling out one of the rumors which has swirled around her death in a car crash six years ago.

Dr. John Burton (search), who was the royal coroner at the time, said he was present at a post-mortem examination after her body was returned from Paris, The Times newspaper reported in Wednesday's editions.

"I was actually present when she was examined. She wasn't pregnant. I know she wasn't pregnant," the newspaper quoted him as saying.

Burton spoke on the same day that the present royal coroner, Michael Burgess (search), opened formal inquests into the deaths of Diana, 36, and her boyfriend, Dodi Fayed (search), 42. They died when their chauffeur-driven car crashed in an underpass in Paris on Aug. 31, 1997.

A French judge laid responsibility for the crash on the driver, Henri Paul, who was found to have been intoxicated and driving at high speed. He was also killed.

Burgess announced Tuesday that he had asked police to look into theories that the princess was the victim of a conspiracy, variously attributed to the royal family and intelligence agencies.

"I'm aware that there is speculation that these deaths were not the result of a sad but relatively straightforward road traffic accident in Paris," Burgess said.

"I have asked the Metropolitan Police Commissioner [Sir John Stevens] to make inquiries. The results of these inquiries will help me to decide whether such matters will fall within the scope of the investigation carried out at the inquests," he said.

Fayed's father, Mohammed Al Fayed, has claimed that Diana may have been pregnant when she died. He has also accused Prince Philip, the husband of Queen Elizabeth II, of masterminding a conspiracy.

The Daily Mirror newspaper on Tuesday published a letter apparently written by Diana to her butler, in which she claimed that her ex-husband, Prince Charles, was plotting to kill her in an auto accident.

The Daily Mirror itself described the idea as "utterly preposterous to many people" and said there was no evidence to support the claim.

Burgess adjourned both inquests at least until early next year, to give him time to collect evidence, read the French police reports and to give British police time to complete their investigations.