ITV News Royal Editor Chris Ship has analysis on the reaction
Lord Dyson has been appointed to lead the independent investigation in a bid "to get to the truth”, the BBC announced earlier today.
William, who is understood to have “tentatively welcomed” the investigation, said tonight: “The independent investigation is a step in the right direction.
“It should help establish the truth behind the actions that led to the Panorama interview and subsequent decisions taken by those in the BBC at the time.”
The investigation, which will begin immediately, will seek to discover what steps Bashir and the BBC took to land the explosive interview 25 years ago.
It comes after recent allegations by Diana’s brother, Earl Spencer, that he was shown “false bank statements” by Bashir to help gain access to the Princess.
She famously told him: "Well, there were three of us in this marriage, so it was a bit crowded."
The investigation will consider if steps taken by Bashir and the BBC were appropriate and to what extent those actions influenced Diana’s decision to give an interview.
It will also investigate what knowledge the BBC had of "mocked up bank statements purporting to show payments to a former employee of Earl Spencer (and) the purported payments to members of the Royal Households”, the corporation said.
Tim Davie, Director-General of the BBC, said: “The BBC is determined to get to the truth about these events and that is why we have commissioned an independent investigation.
“Formerly Master of the Rolls and a Justice of the Supreme Court, Lord Dyson is an eminent and highly respected figure who will lead a thorough process.”
The BBC recently said it had “recovered” a lost handwritten note from Diana which allegedly confirms the false bank statements played no part in her decision to speak on camera.
The note has been passed on to the independent investigation.
Lord Dyson said: “This is an important investigation which I will start straight away. I will ensure it is both thorough and fair.”
Bashir, who is now religion editor at the BBC, is currently signed off from work.
A statement from the corporation said: "He is currently recovering from quadruple heart bypass surgery and has significant complications from having contracted Covid-19 earlier in the year."
The BBC will publish a report of the investigation at its conclusion.