THE investigation into the death of Diana, Princess of Wales, has been much more complicated than any of those involved had anticipated, Lord Stevens of Kirkwhelpington, the former Metropolitan Police Commissioner, has disclosed.

More than two years after Operation Paget was set up, Lord Stevens said that he was still not in a position to rule out some of the conspiracy theories that surround the death of the Princess.

Lord Stevens said that Mohamed Al Fayed — who claims that the Princess and his son, Dodi, were killed by British security services — had been right to raise some of his concerns about the car crash in a Paris underpass on August 31, 1997.

The Scotland Yard inquiry was ordered two years ago by Michael Burgess, the Royal Coroner, amid continuing conspiracy theories over the deaths.

Mr Al Fayed, the owner of Harrods, who now lives most of the year in Switzerland, has repeatedly claimed that the Princess and his son were victims of a plot that was orchestrated by the Duke of Edinburgh and carried out by the British intelligence services.

A 15-strong team led by Lord Stevens has spent two years interviewing witnesses and examining the events that led to the fatal crash.

“We have new witnesses, we are re-examining other witnesses, and at the end of the day I think what people want is a thorough investigation going where the evidence takes us and . . . some of the answers to some of the questions that have been raised in national newspapers and in other parts of the world. That is the job I have been asked to do and that is the job I’ll do,” Lord Stevens said in an interview on The Sunday Programme for GMTV.

Lord Stevens, pressed on why the inquiry was taking so long, said that it was “far more complex than any of us thought”.

“It is right to say that some of the issues that have been raised by Mr Al Fayed have been right to be raised. We are pursuing those. We have had a lot of co-operation from the French authorities, we have had the car back in this country, which is being examined, and we are looking at a lot of other issues.”

Detectives, helped by crash specialists, are examining the wreck of the car in which the Princess, Dodi Fayed and Henri Paul, their chauffeur, died after the car hit a concrete pillar in the Pont d’Alma tunnel.

Scotland Yard has always regarded the black Mercedes S280, which was delivered to the investigation team last August, as the key to establishing the cause of the accident.

The team has created a three-dimensional computer model of the crash scene and its experts are exploring theories that the vehicle was tampered with.

Last month it emerged that the Prince of Wales had met Lord Stevens as part of the inquiry. Lord Stevens questioned the Prince for several hours.

A two-year investigation in France blamed Mr Paul for losing control of the car because he was high on drink and prescription drugs and driving too fast. However, French police have been accused of botching vital forensic tests, ignoring key witnesses, overlooking evidence and preventing important outside agencies, including DaimlerChrysler, the maker of the Mercedes, from contributing to the inquiry.

The interview is due to be broadcast on GMTV this Sunday between 6.10am and 7.30am.

Explore UK News

• Crime News

• Education News

• Health News

• Scotland News

Times Recommends

• UK regional accents thrive against the odds
• ‘Scarecrow’ wind farms put rare birds to flight
• What an anti-climax: G-spot is a myth