The British government vowed on Friday to examine how the BBC was run, after a damning inquiry into how the broadcaster got its bombshell 1995 interview with Princess Diana and unprecedented criticism from her son Prince William.

An independent investigation concluded on Thursday that journalist Martin Bashir lied and deceived to persuade Diana to agree to the interview in which she disclosed intimate details of her failed marriage to heir to the throne Prince Charles.

It also lambasted the BBC for its "woefully ineffective" investigation into Bashir's actions the following year and for covering up his wrongdoing. Bashir tricked Diana's brother into thinking her staff were spying on her, and could not be trusted.

In a scathing statement, Diana's eldest son William, now 38, called the way the interview was secured "deceitful".

"It brings indescribable sadness to know that the BBC's failures contributed significantly to her fear, paranoia and isolation that I remember from those final years with her."

His younger brother Prince Harry said the interview was part of a series of unethical practices that ultimately cost his mother her life.

"Our mother lost her life because of this, and nothing has changed," he said.

Diana died aged 36 in a Paris car crash in 1997 having become an effective outcast from the royal family, which she suspected of trying to undermine her as her relationship with Charles, William's father, collapsed.

The BBC has apologised for its failings, but ministers, newspapers, critics and some supporters said the episode raised questions for the publicly-funded broadcaster.