The apology comes after an independent inquiry into the BBC interview found that Martin Bashir “deceived and induced” Princess Diana’s brother Earl Spencer to secure the interview. Bashir last week left the BBC, citing health issues.
Martin Bashir, the BBC journalist who tricked Princess Diana into giving an explosive interview, has apologised to Prince William and Harry, but said claims linking his actions to her death were "unreasonable".
A report by retired senior judge John Dyson published on Thursday found that Bashir commissioned faked bank statements that falsely suggested some of Diana's closest aides were being paid by the security services to keep tabs on her.
Bashir, 58, then showed them to Diana's brother Charles Spencer in a successful bid to convince him to arrange a meeting between himself and Diana and earn her trust.
READ MORE: Probe finds BBC reporter tricked Princess Diana into explosive interview
Bashir told the Sunday Times he was "deeply sorry" to Diana's sons Prince William and Prince Harry.
"I never wanted to harm Diana in any way and I don't believe we did," he told the paper.
But William said Bashir's actions and the interview had made "a major contribution" to the demise of his parents' relationship and "contributed significantly to her fear, paranoia and isolation" in her final years.
In his own release, Harry said that the deceptive practices had played a part in his mother's death.
"The ripple effect of a culture of exploitation and unethical practices ultimately took her life," he said.
Diana died in a Paris car crash in 1997, aged 36.
Bashir disputed the accusations, saying "I don't feel I can be held responsible for many of the other things that were going on in her life, and the complex issues surrounding those decisions.
"The suggestion I am singularly responsible I think is unreasonable and unfair," he told the paper.
READ MORE: World commemorates 20th anniversary of Diana's death
'I loved her'
He argued that the 1995 interview had been conducted on Diana's terms, and that they remained firm friends after it aired to an audience of 22.8 million people.
"My family and I loved her," he said, revealing that Diana had visited Bashir's wife and newborn child in hospital and that the princess threw a birthday party for his eldest child at Kensington Palace.
Bashir has said that he regretted showing Diana's brother forged documents, but that it had "no bearing" on the revelations aired during the interview.
In it, Diana famously said "there were three people" in her marriage -- her, Charles and his long-time mistress and now wife, Camilla Parker-Bowles -- and also admitted adultery.
Bashir was little-known at the time but went on to have a high-profile career on US television networks, and interviewed stars such as Michael Jackson.
The pop singer's family also blames Bashir for his death, saying the fallout from the interview led to him increasingly dependent on drugs.
Tony Hall's resignation
Bashir worked for the BBC as religion editor until he stepped down just last week, citing ill health, hours before Dyson's report was submitted to BBC bosses.
Former BBC chief Tony Hall, whom Dyson criticised for his "woefully ineffective" 1996 probe into Bashir's deception, resigned as chair of Britain's National Gallery on Saturday.
A government review of the BBC's funding and governance is due next year, which Home Secretary Priti Patel on Sunday called a "very, very important moment."
"There's no question about that trust and confidence has been undermined, and now it's a time for the BBC to absolutely reflect upon the findings of this report and rebuild that trust and confidence," she told Sky News.