LONDON — The British Broadcasting Corporation has offered an unconditional apology after a report found a prominent journalist used "deceitful" methods to secure a landmark interview with Princess Diana as her marriage broke down.

BBC journalist Martin Bashir conducted the career-defining interview with Diana in 1995, in which she detailed the breakdown of her relationship with Prince Charles.

BBC Director-General Tim Davie said on Thursday the interview "fell far short of what audiences have a right to expect."

"While the BBC cannot turn back the clock after a quarter of a century, we can make a full and unconditional apology. The BBC offers that today," Davie said.

The report found that Bashir had shown fake bank statements to Diana's brother Charles Spencer, which "deceived and induced him to arrange a meeting with Princess Diana."

"By gaining access to Princess Diana in this way, Mr. Bashir was able to persuade her to agree to give the interview," the report notes, adding that this behavior was in breach of BBC guidelines.

Bashir has long been alleged to have used forged documents that suggested the palace staff were working against Princess Diana and being paid to spy on her, CNN anchor and correspondent Max Foster has previously reported.

Matt Weissler, a former graphic designer for the BBC, said he mocked up false bank statements after Bashir reached out to him.

The 1995 interview was a seismic moment in British public life.

During the event, Diana told Bashir that there were "three of us" in her marriage to Charles, referring to Camilla Parker Bowles, whom the heir to the throne would later marry.

Buckingham Palace was blindsided by the interview and thrown into crisis by Diana's comments, which cast a rare light on the inner workings of the royal family.

Last week Bashir stepped down from his role as the BBC's religion editor, citing health reasons.

On May 14, Jonathan Munro, the BBC's Deputy Director of News, sent an email to staff confirming that Bashir would leave the corporation.

"He let us know of his decision last month, just before being readmitted to the hospital for another surgical procedure on his heart," the email read. "Although he underwent major surgery toward the end of last year, he is facing some ongoing issues and has decided to focus on his health. We wish him a complete and speedy recovery." — CNN