Robert Verkaik: Why verdict will not silence the conspiracy theorists

Those hoping that the jury's verdicts on the deaths of Diana, Princess of Wales and Dodi Fayed would silence the conspiracy theorists will be disappointed.

History shows that the legal process is inadequately equipped and was never designed to answer allegations based on rumour, hearsay or speculation.

Mohamed Al Fayed's central accusation – that the Duke of Edinburgh ordered the murder of his son and Princess Diana – may have been completely demolished under the strict rules of evidence but there are plenty of questions arising out of the inquiry to keep the conspiracy alive.

Mr Al Fayed will no doubt make a great deal of the coroner's decision to refuse to call Prince Philip as a witness and to withdraw from the jury the opportunity to find that Diana and Dodi were unlawfully killed in a plot organised by the Royal Family. Under the coroner's rules, Lord Justice Scott Baker had a duty in law to dismiss such a possibility if he decided the evidence could not support that verdict.

But conspiracy theorists are no respecters of the finer points of law and will use the coroner's intervention as justification for adding his name to the now long list of establishment figures who it is alleged have tried to cover up the truth. However, it was Lord Justice Scott Baker himself who during his summing up to the jury highlighted the inquest's shortcomings.

He regretted, for example, that the inquest did not have the power to compel some of the French witnesses to attend the court. In particular he said he was disappointed that the French authorities did not intervene to force the paparazzi to testify and it was a "great pity" that some of the French medical experts had not given direct testimony to the court.

It emerged halfway through the inquest that the decision had been taken not to compel witnesses to give evidence, prompting Michael Mansfield QC, for Mr Al Fayed, to call on Jack Straw to make representations to France on the issue.

Lord Justice Scott Baker was one of the first to recognise that the inquest would not bring closure to the debate. He told the jury in his summing up: "There are no doubt those who genuinely believe this to be the case and will continue to do so regardless of any verdict you return."

He could have gone further by pointing out that, 45 years after the assassination of President John Kennedy, a series of inquiries and court cases have emphatically failed to extinguish the conspiracy theories surrounding his death.