The coroner, Lord Justice Scott Baker, also pressed Burrell to turn over the materials on the basis that he would review them first to determine if they have any relevance to the inquest into the death of Diana and her boyfriend, Dodi Fayed, on Aug. 31, 1997.
When he was asked which member of the royal family had warned Diana about surveillance, Burrell wrote the name and then handed it to Baker, who said he believed it had no relevance to the inquiry.
As for the secret he shared with the princess - a secret he referred to in "A Royal Duty" - he first refused to say what it was, and then said he did not remember. Regardless, he said it had nothing to do with Fayed.
Burrell, Diana's confidante for a decade, said the princess gave no indication that she intended to marry Fayed and made no arrangements to announce an engagement before she died as Fayed's father claims.
Burrell described Diana's romance with Fayed as a "30-day relationship," saying she was still recovering from the end of a secret two-year relationship with heart surgeon Hasnat Khan. In an interview published in British newspapers Sunday, Khan declined to discuss the reasons for the end of his relationship with Diana.
"The princess had just finished a long-term relationship with someone she cared deeply about," Burrell said. "I know that, because I was there. I saw it."
Burrell described Diana as being "on the rebound from that relationship when she met someone who was very kind and attentive and generous."
Under pressure from Baker, Burrell reluctantly disclosed a harsh conversation between Diana and her mother, the late Frances Shand-Kydd.
Burrell said Diana invited him to listen in on the call, and he heard the mother say Diana was "a whore" who was messing around with Muslim men.
"She said some very nasty things," Burrell said.
Burrell has previously disputed claims by Fayed's father, Mohamed Al Fayed, that Diana was pregnant with Fayed's child and that the couple were on the brink of announcing their engagement when they died after their car slammed into a pillar in the Pont d'Alma tunnel in Paris.
"'I want another marriage like I want a bad rash,"' Burrell quoted Diana as saying in a telephone conversation when she was with Fayed in France.
Al Fayed has also claimed that his son and Diana were the targets of a conspiracy directed by Prince Philip, the husband of Queen Elizabeth II.
Burrell said he had seen correspondence between Diana and Philip in 1992, when efforts were being made to save her marriage to Prince Charles.
Diana's friend, self-described "energy healer" Simone Simmons, testified last week that she had seen two letters from Philip that were "derogatory" and cruel, and upsetting to the princess.
"Yes, they were sharp," Burrell said of the letters he saw. "Prince Philip doesn't mince his words; he says it as it is, but he is not a nasty man."
He added that Diana "didn't particularly like sometimes what she was told, but Prince Philip was always frank." "The princess fired off equally as robust words to Prince Philip," Burrell said.
Burrell has said that after Diana's death, the queen warned him to be careful and told him, "There are powers at work in this country of which we have no knowledge."
He testified that he was unsure whether she referred to the media, the "Establishment," or the secret services. "One doesn't ask the queen what she means by something," Burrell said. "I just think it was a general 'be careful' warning over many issues."
