Martin Bashir says he "deeply regrets" his action after a report found he used "deceitful behaviour" to secure his 1995 Panorama interview with Princess Diana.
What did Diana's brother allege?
Earl Spencer claimed that in the weeks before the programme, Mr Bashir showed him forged bank statements that related to alleged payments made to his sister's former private secretary Patrick Jephson and another former royal household member by the security services.
The documents falsely suggested the individuals were being paid for keeping the princess under surveillance.
Mr Bashir also showed him mocked-up documents, relating to a former employee of the earl, that Mr Bashir also used as he tried to gain access to the princess.
What are the main findings of the 127-page report?
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• Mr Bashir commissioned fake bank statements from graphic designer Matt Wiessler, purportedly showing payments by Penfolds Consultants and News International into the bank account of Alan Waller, a former employee of Earl Spencer
• Mr Bashir showed the documents to Earl Spencer on a date early in September 1995. The report said Mr Wiessler is an entirely reputable graphic designer who did freelance work for the BBC. Nobody has criticised him for accepting the commission
• A few days later, probably on 14 September, Mr Bashir also produced to Earl Spencer other bank statements which, he said, showed payments into the account of Mr Jephson and Richard Aylard (the Prince of Wales' former private secretary)
• The report said it is likely that these statements were created by Mr Bashir and contained information he had fabricated
• By showing Earl Spencer the fake Waller and Jephson/Aylard statements and informing him of their contents, Mr Bashir 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 inquiry found this behaviour was in serious breach of the 1993 edition of the BBC's Producer Guidelines on straight dealing
• The BBC "fell short of the high standards of integrity and transparency which are its hallmark" in the subsequent investigation
• A 1996 investigation conducted by Lord Hall, who was director of BBC news and current affairs when the Diana interview was screened, and Anne Sloman was woefully ineffective, the report found
• The new inquiry said they failed to interview Earl Spencer, which "was a big mistake"
• They did not scrutinise Mr Bashir's account with the necessary degree of scepticism and caution: they knew he had lied three times when he said that he had not shown the fake statements to Earl Spencer (these were serious lies for which he gave no explanation)
• They knew that he had been unable to provide any credible explanation of why he had commissioned the fake statements (which was a serious breach of the BBC's Producers' Guidelines on straight dealing); and they knew that Mr Bashir's account of what happened was largely uncorroborated
• And without knowing Earl Spencer's version of the facts; without receiving from Mr Bashir a credible explanation of what he had done and why he had done it; and in the light of his serious and unexplained lies, Lord Hall could not reasonably have concluded, as he did, that Mr Bashir was an honest and honourable man
Martin Bashir's reaction
In response to Lord Dyson's findings, Mr Bashir apologised, saying the faking of bank statements was "a stupid thing to do and was an action I deeply regret".
But he added he felt it had "no bearing whatsoever on the personal choice by Princess Diana to take part in the interview".
Lord Hall's reaction
Former director-general Lord Hall has apologised that the 1996 inquiry "fell well short of what was required".
He said: "I have read Lord Dyson's report, and I accept that our investigation 25 years ago into how Panorama secured the interview with Princess Diana fell well short of what was required.
"In hindsight, there were further steps we could and should have taken following complaints about Martin Bashir's conduct."
He added: "I was wrong to give Martin Bashir the benefit of the doubt, basing that judgment as I did on what appeared to be deep remorse on his part."
According to the report, the BBC without justification "fell short of the high standards of integrity and transparency which are its hallmark by covering up in its press logs such facts as it had been able to establish about how Mr Bashir secured the interview and failing to mention Mr Bashir's activities or the BBC investigations of them on any news programme".
The BBC's reaction
The corporation's director-general, Tim Davie, says the BBC offers a "full and unconditional apology".
He said: "While today's BBC has significantly better processes and procedures, those that existed at the time should have prevented the interview being secured in this way. The BBC should have made greater effort to get to the bottom of what happened at the time and been more transparent about what it knew.
"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."
Lord Birt's reaction
Lord Birt, director-general of the BBC at the time of the interview, said: "We now know that the BBC harboured a rogue reporter on Panorama who fabricated an elaborate, detailed but wholly false account of his dealings with Earl Spencer and Princess Diana.
"This is a shocking blot on the BBC's enduring commitment to honest journalism; and it is a matter of the greatest regret that it has taken 25 years for the full truth to emerge.
"As the director-general at the time, I offer my deep apologies to Earl Spencer and to all others affected."
In March this year, the Metropolitan Police said Mr Bashir will not face a criminal investigation over documents related to the landmark Diana interview.