Prince Charles had to answer some questions about Princess Diana's death in a top-secret meeting with the U.K. police in 2005. The investigation, called Operation Page, addressed the conspiracy theories about the tragic 1997 accident that left the Princess of Wales dead.

Former Scotland Yard head John Stevens revealed the events during the interview that occurred at St. James' Palace in London without anyone knowing. He told the Daily Mail that there were only four of them during the meeting: Charles, his private secretary Sir Michael Peat, him and his senior investigator Dave Douglas.

Stevens described the interview as "unique" but clarified their approach to the future king was just like anybody else. Everything started with small talk until he read aloud a note that Diana wrote.

The note claimed her then-husband was planning "an accident in her car, brake failure and serious head injury." He allegedly did this to marry Prince William and Prince Harry's nanny, Tiggy Legge-Bourke.

According to People, she even alleged Charles' wife, Camilla, Duchess of Cornwall, was a "decoy." Stevens then questioned the Prince of Wales if he knew anything about it.

"I did not know anything about [the note] until it was published in the media," the royal said. He added he did not know that such a letter ever existed, let alone she felt that way.

The former officer even commended Charles for being cooperative because "he had nothing to hide."

Stevens then admitted several allegations were made against Charles and other royal family members, but they first examined the evidence authenticity before they performed an inquiry. "We found no other evidence to support the scenario suggested in Diana's note," he said, Yahoo News noted.

Diana's note was deemed to make Charles a formal suspect. Anyhow, his late father, Prince Philip, declined to assist in the investigation back then.

When asked if he wanted to comment on the issue, he simply said: "No, thank you."

Diana's note was said to be written around her Martin Bashir interview on the BBC's "Panorama." However, the said talk was also not shy of controversy.

Former Supreme Court judge John Dyson claimed Bashir used "deceitful methods" to have an explosive, tell-all interview with the late Princess. The reporter allegedly breached the editorial guidelines when he created two false bank statements that he showed Diana's brother, Earl Charles Spencer, which resulted in Diana's meeting and interview with Bashir.