London ? British police have doubts about the authenticity of the blood sample that led French investigators to conclude drunken driving caused the car crash that killed Princess Diana, a newspaper reported Saturday.

The Times of London reported that senior officers were concerned that no DNA test was conducted to prove the blood belonged to Henri Paul, chauffeur of the car that crashed Aug. 31, 1997, in Paris.

Princess Diana, her boyfriend, Dodi Fayed, and Paul all were killed in the crash, which a French court ruled in 2002 was an accident caused by Paul’s speeding and being under the influence of alcohol.

A police spokesman said Saturday the force had no comment on the Times report.

French police inspector Jean-Claude Mules, who played a central role in the investigation, told The Times there was no mistake about the blood sample. “We are very serious people, and no errors are allowed,” he was quoted as saying.

Many people continue to believe that Diana was the victim of a conspiracy, however, variously pointing to the royal family and intelligence agencies.

British coroner Michael Burgess, who opened an inquest into the deaths of the princess and Fayed this week, has asked London’s Metropolitan Police to investigate whether there was any evidence the deaths were not the result of a “straightforward road traffic accident.”

The Times said there were “high-level concerns” that Paul’s blood could have been mixed up with another sample in a laboratory or the mortuary where his body was taken.

It said the sample tested contained extremely high levels of carbon monoxide that could have rendered Paul incapable of driving.