Given the nature of her life, there was never any likelihood that the death of Diana, Princess of Wales would be allowed to pass unchallenged into history as something so prosaic as a car accident. Almost from the moment the Mercedes in which she was travelling with her companion Dodi Fayed crashed in a Paris tunnel in August 1997, the conspiracy theorists have had a field day, sustained throughout by the bloody-minded determination of one man to prove something that all sensible people knew to be nonsense.

Mohamed Fayed was understandably grief-stricken by the loss of his son. But his efforts in the intervening years to sully the reputations of the Royal Family, the security and intelligence services, the Metropolitan police, the British judicial system, sundry diplomats and, indeed, anyone who did not share his paranoid convictions, have long since destroyed any residual sympathy for his predicament. His persistent legal challenges to the medical and judicial conclusions of the French authorities were the principal reason why it has taken so long to hold an inquest. The bizarre spectacle of MI6 officers being asked in the High Court of Justice whether they had received instructions from the Duke of Edinburgh to assassinate his erstwhile daughter-in-law owed everything to a perceived need to assuage Mr Fayed's ludicrous fantasies.

The resulting inquest, which should have been a dignified and sombre affair, became a circus. This is not meant as a criticism of Lord Justice Scott-Baker, who has handled this extraordinary event with professionalism and skill. In order to scotch the wilder theories propounded by Mr Fayed, the coroner has allowed them all to be aired, however unedifying the spectacle and despite the further anguish thereby inflicted upon the Princess's two sons. Mr Fayed was never willing to confront the most plausible cause of the tragedy: that the Ritz driver Henri Paul, his judgment impaired by drink, drove too fast in the underpass and crashed the car which his employer suggested he should drive.

Now, more than a decade after the crash, the inquest has returned a verdict of unlawful killing due to the gross negligence both of Mr Paul and the paparazzi who were pursuing the Mercedes. Mr Fayed has nowhere else to go. It is tempting to suggest that he should now be required to pay the £10 million costs to the taxpayer of the inquest and of Lord Stevens's separate inquiry that also concluded the crash had been an accident.

There is, too, a strong case for charges of perjury to be brought against those whom the coroner said had lied to the inquest. But this would simply prolong what has already been a colossal and distressing waste of time. This must stop here: let the victims of this tragic affair now rest in peace.