“There were three of us in this marriage, so it was a bit crowded,” the princess said from her Kensington Palace home.
The interview also explored Diana’s battle with bulimia – a prominent plot line in the new season of the hit Netflix series The Crown.
Spencer has recently claimed that Bashir used wild allegations and forged documents to play to his late sister’s insecurities and win her trust.
The BBC apologised in October after admitting Bashir had used fake bank statements to claim that Spencer’s former head of security and members of the royal household were receiving payments from media companies, including Rupert Murdoch’s News International group.
Bashir allegedly showed Spencer the forged documents to win his trust and secure an introduction to Diana.
The reporter also allegedly told Diana that her correspondence had been intercepted, her phone lines at Kensington Palace tapped and a tracking device installed in her car. He also allegedly said the princess had been followed by security services, and that her bodyguard was plotting against her.
Bashir is now the BBC’s religion editor.
The broadcaster has previously said the 57-year-old was unable to answer questions about his conduct because he was “seriously unwell” with complications from coronavirus and quadruple heart bypass surgery. He was recently photographed walking between his London home and an Indian takeaway and wine shop.
BBC director-general Tim Davie said he was determined to discover the truth about events before, during and after the interview.
The investigation will commence immediately and the BBC is already handing over all relevant records, Davie said. He also vowed to publish the investigation once it is finished.
Lord Dyson’s terms of reference include finding out what steps the BBC and Bashir took to obtain the interview. All allegations recently made by Spencer will be examined.
The probe will also consider whether those actions fit with the BBC’s editorial standards at the time and to what extent the BBC and Bashir influenced Diana’s decision to grant the interview.
Critically, Lord Dyson has been asked to discover what knowledge the public broadcaster had in 1995 and 1996 when it cleared Bashir of previous claims of misconduct and whether the BBC did enough to get to the truth.
Spencer has said he long knew Bashir had duped him and Diana into the interview but had only recently learnt through freedom-of-information requests that the BBC was aware of Bashir’s alleged methods and “covered it up”.
Fieldfisher LLP, a European law firm, has been hired to assist Lord Dyson.
The BBC said the firm had a track record of helping major public inquiries and investigations, including the inquest into the death of Diana and her partner Dodi Al Fayed in Paris in 1997, the 2005 London terrorist bombings, and the inquiry into the poisoning of former Russian spy Alexander Litvinenko in London in 2006.
Bevan Shields is the Europe correspondent for The Sydney Morning Herald and The Age.