LONDON, England (CNN) -- Claims by Diana's former butler that he knew a mysterious "secret" about the late princess have been trashed by the coroner in her inquest.



Diana's former butler has given conflicting information at the enquiry into her death.



The coroner said the information was already in the public domain and some of it was even mentioned in one of Paul Burrell's own books.



Considered the first star witness of the inquest, Burrell's appearance Tuesday was delayed after the coroner asked him to retrieve the last letter the princess gave him.



Monday, the ex-butler -- once described by the princess as "her rock" -- told the inquest the letter contained a "secret," which he claimed he could not remember.



After returning to London from his home in northern England Tuesday, Burrell said the letter was not there, but at his home in Florida. He then handed the coroner a note that he said contained the supposed secret.



The coroner revealed that what Burrell referred to was that Diana was planning to buy property to live in part of the time and that the location may have been in the United States or South Africa.



The coroner said the revelation is "fairly and squarely in the public domain" and that some of the information appeared in Burrell's book "The Way We Were."



Explaining the apparent discrepancies in his testimony, Burrell said he was confused by the cross-examination, which he described as "horrid" and "disgraceful."



The questioning of the former butler is expected to continue Wednesday.



Diana and her boyfriend, Dodi Fayed, died in a Paris tunnel in the early hours of August 31, 1997, along with their driver, Henri Paul. They had driven away from the Ritz Hotel in a black Mercedes with paparazzi chasing behind.



There has been speculation that the couple had planned a big announcement the night they died. Photographers have testified they had heard rumors Diana would say she was getting engaged to Fayed or having a baby.  Watch report on claims about Diana's marriage plans »



Burrell did not take the stand until Tuesday afternoon.



Earlier in the day, the inquest heard from Diana's former lawyer, who said the princess had claimed Queen Elizabeth was planning to abdicate in April 1996 and allow Prince Charles to be king.



Maggie Rae said at the inquest that Diana also believed there was a plot to seriously injure her in an accident.



Rae said the claims came at a meeting with her legal team at Kensington Palace in which the princess also made clear her belief that the succession of the English crown should skip a generation to her son, William.



The morning's evidence also heard that Britain's top police officer had advised the queen against allowing Diana to go on holiday with Mohamed al Fayed, the father of Dodi.



In a note from Chief Superintendent Dai Davies, head of the Royal Protection Squad, that was read out to the court, it was stated that he and Metropolitan Police Commissioner Sir Paul Condon believed that the planned holiday was "unwise."



Al Fayed -- a successful businessman and owner of the London luxury store Harrods -- was considered a controversial figure at the time.



Diana defied the advice and went on the trip. It was during this holiday on the tycoon's luxury yacht in the French resort of St. Tropez that she met Dodi Fayed.



During her testimony, Rae also gave an insight into the princess's lifestyle, which she described as "odd" and "lonely."



She said she did not believe Diana's claims of a conspiracy against her.



"I remember one occasion when she told me about her weekend and she had been alone in those rather silent set of apartments. She had heated her own food in the microwave," Rae told the court.



"I thought she lived in a very odd environment. I thought she was quite lonely." E-mail to a friend



CNN's Melissa Gray contributed to this report.
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