But Michael Mansfield, QC, for Dodi’s father Mohamed Al Fayed, told the hearing yesterday: “The Paget report never does indicate it saw the original, and there are differing police recollections as to whether they did so.” He asked for tests to find indentations that might reveal the existence of a still-concealed top page containing a date and the name of the intended recipient.

The development came as the coroner overseeing the inquest rejected calls for the Queen and Prince Philip to be questioned as witnesses. Lord Justice Scott Baker’s decision infuriated lawyers trying to investigate claims that Diana was murdered.

He insisted it was neither appropriate nor necessary to ask Philip about letters he is said to have written to the Princess and to question the monarch about a warning that she is alleged to have given Mr Burrell about “dark forces” at work.

The refusal came despite claims by Mr Al Fayed that the couple were murdered in an MI5 plot masterminded by the Duke of Edin­burgh because Diana was pregnant with Dodi’s child.

Philip refused to cooperate with the Scotland Yard inquiry led by ex-Metropolitan Police Commis­sioner Lord Stevens, insisting he had nothing useful to add.

Mr Mansfield urged the coroner to help uncover the truth about Philip’s letters, which were said to have upset Diana.
“You may be able to approach him on behalf of the inquest and inquire into truth,” he said. “Ob­vious inquiries are, firstly, whether he was aware of any of the fears she has expressed and, two, whether he did send letters of the kind described in the Paget report.”

But Lord Justice Scott Baker said: “It doesn’t seem to me that any further inquiries at this stage would be appropriate or necessary.” But he said he would “keep the position under review”.

Last night Mr Al Fayed vowed to press ahead with efforts to obtain evidence from the Royal Family, which he says will support his murder claims.

“The coroner may believe it is not appropriate nor necessary but we believe it is,” said a spokesman for the Harrods tycoon. “At some point we’re going to have to have answers. We’re not going to let this drop.”

Another mystery surrounding the case has also been the allegation that a white Fiat Uno caused Diana’s chauffeur-driven Mercedes to veer out of control.

There have been claims that it belonged to James Andanson, a photographer who was later found dead.

His burnt corpse was found in the wreckage of a car in France in what appeared to be suicide.

However, a witness has now come forward to say he believes that Andanson had two bullet holes in his head.

Mr Mansfield also claimed there was a witness, Jacques Morrell, who saw Mr Andanson in Paris on the night of the crash. He said: “There are witnesses who indicate he was in Paris. Whether he was driving a white Fiat Uno is a separate matter.

“Part of (Morrell’s) identification of Andanson comes from something that is referred to as confidential reports.”
He said it was not clear what these confidential reports were, and urged the court to request the information from investigators.

The hearing was also told that a marquee will be set up in the courtyard of the High Court to accommodate hundreds of journalists and members of the public who will want to see the full inquest.

The next preliminary hearing will be held on July 27.