Diana Princess of Wales, was “cast adrift” from the safety of her “royal support structure” and made “vulnerable” after the Panorama interview, it has been claimed.

An inquiry by former master of the rolls Lord Dyson has found that BBC journalist Martin Bashir used false documents to induce Earl Spencer to introduce him to his sister Diana and set up the Panorama exclusive – An Interview With HRH The Princess of Wales – on November 20 1995.

Diana and her lover Dodi Fayed died after their Mercedes, which had a drunk driver at the wheel, crashed in the Pont de l’Alma tunnel as they were pursued by the paparazzi in Paris on August 31 1997.

Diana’s former private secretary Commander Patrick Jephson told a new Panorama programme that after the face-to-face interview, she was “cast adrift” from the “royal support structure that had guided and safeguarded her for so many years”.

He suggested this “inevitably … made her vulnerable to people who did not have her best interest at heart or were unable properly to look after her”.

The Dyson inquiry found that Bashir used “deceitful behaviour” and was in “serious breach” of the BBC’s producer guidelines to secure the 1995 interview.

Earl Spencer told the new BBC programme: “The irony is that I met Martin Bashir on the 31st of August 1995 because exactly two years later she died, and I do draw a line between the two events.”

After he made the introduction, Earl Spencer says it became “quite clear that everyone was going to be made untrustworthy, and I think that Diana did lose trust in really key people”.

He added: “In the end, when she died two years later, she was without any form of real protection.”

The 1995 interview was watched by 23 million people in the UK.

Panorama now says it has seen a confidential internal BBC management document written by the outgoing head of TV Current Affairs, Tim Gardam, which shows that Bashir had misled his bosses.

He had denied showing the fakes to anyone, before admitting that he had passed them on to Earl Spencer in order to “foster” their relationship, according to Panorama.

Instead Lord Tony Hall, who was then the managing director of news when the interview was screened, drew up a statement for the BBC’s governors in April 1996, in which the fakes were described as just “graphics” and that Bashir, who had no explanation for why he had created them, was “even with his lapse, honest and an honourable man”.

Former BBC governor Sir Richard Eyre says the board of governors would have insisted on a full inquiry if they had known about Bashir’s actions.

He told the programme: “The fact that Bashir lied should have been made clear to us, but in my memory, it never was.

“Constitutionally we, the governors deserved at very least to be given an honest report of what was going on.

“We can see now that the false bank statements were the lever that opened the doors to the access to Diana. If we had known at the time, there’s no question that this would have been ruthlessly investigated, because (the governors) were very, very, very hot on a sense of propriety of the organisation.”

It is alleged Diana had been led to believe by Bashir that she was being spied on.

After the 1995 broadcast, BBC management relied on a note from Diana which says she “consented to the interview on Panorama without any undue pressure”.

Earl Spencer does not feel this exonerates the BBC.

Both Lord Hall, who went on to become BBC director-general, and Bashir were contacted for comment before Lord Dyson’s report had been published.

Both men felt they could not fully respond at that point, but Bashir added: “I consider there to be cogent evidence that casts doubt on or even disproves many of the allegations, and I will provide further information when I am able to do so.”

Lord Hall said he had carried out his “responsibilities in good faith” a quarter of a century ago when the corporation investigated whether Diana had been misled.

He said: “It was clear from the correspondence from her that she had not been misled – that she had no concerns, that she had been shown no documents and was glad she had given the interview.

“Given this background, I decided to allow Mr Bashir to continue with a severe reprimand and under close supervision. I was open and transparent with the director-general and with colleagues on the board of management and I believe I gave them all the key facts.

“The minutes of meetings with them will not have fully reflected everything that was said – they never do.”