The revelation came from the princess's former butler Paul Burrell, who gave evidence at the current inquest into Diana's August 1997 death. (Having reopened in October, the inquest is expected to last until March.)
Burrell – who has written two best-sellers on Diana – also told how his former employer planned a secret wedding with Pakistani heart surgeon Hasnat Khan, whom she dated until July 1997. Diana, 36, died the very next month.
The phone conversation cited by Burrell between Diana and her mother Frances Shand Kydd took place in June 1997.
"I sat and listened with the Princess's ear on one side and mine on the other," Burrell told London's High Court.
"She called the Princess a 'whore' and she said that she was 'messing around with effing Muslim men,' and she was 'disgraceful' and said some nasty things," Burrell told the court.
Diana Sought AdviceBurrell, who flew in from his home in Florida to give evidence, had earlier told the inquest that Diana was planning to marry Khan. When the princess had asked him to go and seek some advice, he turned to a Roman Catholic priest in Kensington, London.
Burrell also dismissed talk of a plot to kill the princess – either at the behest of her father-in-law Prince Philip or her ex-husband Prince Charles.
"I just couldn't possibly see the father of her children murdering her," Burrell said.