The inquiry into Princess Diana’s death has been sensationally reopened by a French judge.
It comes amid fresh doubts over scientific tests stating that her death crash driver was drunk.
The director of public prosecutions in France has instructed a judge to question again two forensic experts who led police to reach that conclusion. A source close to the investigation said: “It appears reports have been falsified. There have been many lies and much cheating in this inquiry.
“How is it possible for anybody to believe it was a simple road accident? This was not an accident.”
The two scientific experts could face criminal charges and prison sentences if their new depositions reveal that they lied in the past. The development comes just 10 days before the anniversary of Dian’s death in the Alma underpass, Paris, in 1997.
It follows a series of Daily Express investigations revealing the welter of errors and inconsistencies that shroud the tragic events in mystery.
The latest move make it impossible for investigators to conclude with certainty that Diana and her lover Dodi’s death were the result of a simple road accident and adds further weight to the claims of a cover-up.
Dodi’s father Mohammed Al Fayed said: “This is a huge step – possibly the biggest development – in my fight to get to the truth.
“I have always maintained that Princess Diana and my son were murdered. It goes a long way to help prove that and expose the cover-up.
“I will be fascinated to hear the depositions by these experts.”
French investigators declared that chauffeur Henri Paul was to blame for the accident after relying on blood tests that showed he was three times over the alcohol limit when the Mercedes S280 crashed, killing himself, Diana and Dodi.
The fresh doubts over the tests will certainly delay the submission of the report from Operation Paget, the £4million inquiry into Diana’s death by Lord Stevens, the former Metropolitan Police commissioner.
Thierry Bellancourt, the deputy chief judge at Versailles, has ordered Professor Dominique Lecomte, the controversial pathologist who conducted Paul’s post mortem investigation, and Dr Gilbert Pepin, the toxicologist who tested his blood, to appear in court over their suspect evidence.
The judge has accepted claims – first revealed by the Daily Express – of errors and omissions in the paper trail that led French police to determine that the crash was solely due to Paul’s drink-driving.
New documents handed to the judge reveal that while Lecomte testified on oath that she had taken just three blood samples from Paul, a laboratory log book shows that five samples were taken – raising fears that the extra samples were wrongly attributed to Paul.
They also show how poisons expert Pepin claimed that one sample he tested revealed that Paul had 1.74 grams per litre of alcohol in his blood, but that finding is not supported in his paperwork.
The documents reveal how paperwork relating to a second blood test by the forensic toxicologist gives two widely differing readings for the amount of alcohol in Paul’s blood.
The new evidence strengthens claims that the results were faked. Sources involved in the investigation believe that security services ordered samples from the chauffeur to be switched with those from a suicide victim.
The driver’s body was taken from the Alma tunnel to the Institut Medico Legal mortuary in the Place Mazas for an autopsy which began on Sunday morning. That weekend there were a further 24 bodies awaiting examination. After a battery of tests, Dr Pepin and pathologist Professor Lecomte confirmed Paul’s blood-alcohol level was three times the UK legal limit.
But the blood test results also appear to show that Paul had breathed in an extraordinary level of carbon monoxide before his death, the same amount as a person committing suicide by putting a rubber hose from the exhaust into the window of his car. The high level – 20.7 per cent – would have left Paul on the verge of coma, certainly unable to stand and quite incapable of piloting a car at speed through the streets of Paris.
Yet at the Ritz hotel earlier that evening, minutes before he drove Diana to her death, CCTV cameras show him walking normally and even kneeling down to retie his shoelaces. It is also known that Paul was killed instantly by the impact, ruling out any possibility that he inhaled poisonous exhaust fumes. When Dodi’s blood was tested, it showed no signs of carbon monoxide.
A later search by police of Paul’s flat and the Ritz failed to discover any faulty gas heaters which could have been leaking carbon monoxide.
Even Judge Herve Stephan, who conducted the original probe into Diana’s death, has declared unofficially that the presence of gas in Paul’s blood is a mystery.
Yet many involved in the investigation and the Paul family believe the blood samples with alarming carbon monoxide and alcohol readings are not the chauffeur’s but those of a suicide victim lying in the mortuary that night.
Adding to the belief of Mr Fayed and friends of Diana that there has been a massive cover-up by MI6 and the French equivalent, the DGSE, authorities in Paris have repeatedly refused requests to reveal the identity of the other 24 victims in the mortuary.
There is no suggestion that either expert acted improperly but the security source claims that the judge firmly believes blood analysis reports may have been falsified or that the samples in storage have in some way been tampered with.
His investigation has been hindered by the death in July last year of a key witness at the forensics laboratory who was in charge of the handling and storage of samples.
The man, whose identity has not been disclosed, was never interviewed by earlier investigators, despite the belief by a number of officials involved in the current probe that he could have provided vital evidence of a cover-up.
The two experts have been left in no doubt how seriously the judge is viewing the new evidence submitted following the bungled French probe, and may face prison.
The new inquiry has also traced a previously unknown witness, a mystery figure identified only by the initial A, who has been ordered to make a deposition in an attempt to crack the tests riddle.
Bellancourt’s inquiry followed intense pressure from Mr Fayed, the owner of Harrods, who believes Diana was murdered by the security services and blood tests tampered with to cover up the murder plot.
Diana’s friend, the author Simone Simmons, welcomed renewed efforts to establish the truth about the night of August 31, 1997, but was scathing about the original efforts of the Paris authorities.
“Now it finally appears that we must rely on English investigators to make up for French mistakes. It is terrible to think it has taken nine years for this to happen,” she said.
“The French haven’t got anything right for years. This is all very sinister and points to a massive cover-up.”
A French policeman who was involved in the initial inquiry said: “It was all too easy to blame the crash on drunk driving. We just hope now that it is not too late to make up for the shortcomings in the inquiry.”