The BBC’s board of directors has approved the appointment of a retired senior judge to lead an independent investigation into the circumstances around a controversial 1995 TV interview with Princess Diana, the broadcaster said Wednesday.

The announcement came after Diana’s brother, Charles Spencer, made renewed claims this month that BBC journalist Martin Bashir used forged statements and false claims to convince the late royal to agree to the interview.

The investigation will consider if the steps taken by the BBC and Bashir were appropriate and to what extent those actions influenced Diana’s decision to give an interview.

John Dyson, a former Supreme Court judge, is “an eminent and highly respected figure who will lead a thorough process,” the BBC said.

Charles Spencer alleged that in the weeks leading to the interview 25 years ago, Bashir made false and defamatory claims about senior royals in order to gain his trust and access to his sister.

The claims included that Diana’s phone was bugged and that her bodyguard was plotting against her. He claimed that Bashir showed him “false bank statements” purporting to show that two senior royal aides were being paid to keep Diana under surveillance.

Charles Spencer has demanded an inquiry and an apology. The BBC carried out an internal investigation when the complaints first surfaced and has said Bashir admitted commissioning mocked-up documents. But the corporation has said that the documents played no part in Diana's decision to take part in the interview.

The broadcaster’s director general, Tim Davie, said the BBC “is determined to get to the truth about these events.”

The 1995 interview, in which Diana famously said “there were three of us in this marriage” — referring to Prince Charles’ relationship with Camilla Parker-Bowles — was watched by millions of people and sent shockwaves through the monarchy.

Diana divorced from Charles in 1996 and died in a Paris car crash in 1997 as she was pursued by paparazzi. Charles married Camilla, now the Duchess of Cornwall, in 2005.

The BBC said Bashir, 57, who is currently its religion editor, is signed off work by his doctors because he is recovering from heart surgery and complications related to contracting COVID-19 earlier this year.