The Queen did not come forward earlier in Paul Burrell's theft trial because she believed the information she had was "irrelevant", it has been claimed.

Sir Michael Peat, the Prince of Wales's private secretary who is to conduct an internal review into the affair, insisted there was no "conspiracy".

He said the monarch came forward as soon as she realised, from reading the newspapers, that the information could be important.

He said: "The conspiracy theories are, the politest you could say, implausible.

"I can give you my 100% assurance that there was no interference at all.

The conspiracy theories are, the politest you could say, implausible

Sir Michael Peat

"The Prince of Wales took every step he could not to interfere in the course of the trial."

The information from the Queen was that Mr Burrell had told her he was keeping some items of Diana, Princess of Wales.

That undermined the prosecution case that he had stolen from Diana, and led to the trial collapsing - just as Mr Burrell was preparing to take the witness stand.

Police 'intelligence'

Sir Michael said: "The Queen's role was very limited. She knew Burrell, she saw him in December 1997 at his request, she gave him support - he was distressed.

When the Queen read the newspapers... she realised that what Paul Burrell had said to her was relevant

Sir Michael

"She thought nothing more of the conversation, then quite a period later the investigation into Burrell arose.

"Police... told the Prince of Wales they had intelligence Burrell was selling items overseas and had dressed up in some of Diana, Princess of Wales's clothing.

"So the Queen thought some of her conversation, during which he said he was looking after some of her papers for safekeeping, was not particularly relevant.

"The police never went back to the Prince of Wales to tell him that they did not have any evidence that Burrell was selling items abroad or dressing up in Diana's clothing.

"The Queen therefore continued to believe that police had evidence and therefore that her conversation was not relevant."

Acted 'soon as possible'

In the course of the trial, police confirmed it had turned out there was no such evidence against Mr Burrell.

We were all rather surprised that the information did result in the trial coming to an end

Sir Michael

The Queen told the Prince of Wales her information, and the Prince told Sir Michael, who went to the police.

Sir Michael added: "We were all rather surprised that the information did result in the trial coming to an end."

He said the Royal Family had also been surprised at the aftermath, but were nonetheless "pleased that an innocent man did not go to prison for something he had not done".

"The Queen and the Prince of Wales are delighted for the small part they played in that," he said.

Secrets in court

Parts of the trial were conducted in secret, with evidence being shown to the jury but not read out in open court.

Asked to explain why the trial judge had justified the secrecy as "to protect Princes William and Harry", Sir Michael said that had not been a palace request.

"Some of the items were sensitive, such as photographs of the princes in the bath and some letters.

"It was the judge's decision. It's her job to protect minors and children in court cases."