Al-Fayed expanded his theory to include a cover-up by the French police, the British CID and the United States FBI, among others. However, when at the end of the proceedings the coroner gave a detailed summing up of all the evidence, he told the jury that there was ‘not a shred of evidence’ in support of Al-Fayed’s theory that Prince Philip had ordered MI6 to murder Diana, and he questioned Al-Fayed’s credibility as a witness. He explained that he had made the decision not to hear evidence from Prince Philip: ‘In the light of all the evidence we have heard which provided no evidence whatsoever for the suggestion that he was involved in killing his daughter-in-law and Dodi.’ The inquest also shed new light on Prince Philip’s relationship with Princess Diana when it demanded that their correspondence be made available, some of which had already appeared in her butler Paul Burrell’s book. He was not happy about any of it, but there was little he could do. Once revealed, the letters in question showed that he and Diana – at one time at least – had a very good relationship. She addressed him throughout as ‘dearest Pa’ and one of the letters began ‘Dearest Pa, I was particularly touched by your most recent letter which proved to me, if I didn’t already know it, that you really do care.’

According to Simone Simmons, Diana’s healer, who knew her better than most, there were other letters that were written in quite a different tone. Prince Philip denied this and issued a statement through his office in Buckingham Palace saying so. He regarded the suggestion that he used derogatory terms to describe Diana as a ‘gross misrepresentation of his relations with his daughter-in-law and hurtful to his grandsons’.

Diana had always acknowledged that Prince Philip’s letters were helpful in the beginning, but as things became more difficult his tone changed. He had said her actions were damaging the royal family – which indeed they were. She also said that he had insisted that both William and Harry were subjected to DNA tests in the light of her affair with James Hewitt becoming public. There is nothing to prove this is correct, only the hearsay of others, but what was certain was that Prince Philip had moved to the top of Diana’s hate list.