A body language expert has spotted a revealing finger gesture used byPrincess Diana’s brother during his interview on Sunday evening.

Earl Spencer used a conversation with the BBC to repeat his incendiary allegations that King Charles sounded ‘giddy’ after Diana’s death, and told him ‘Rest assured, we’ll forget her soon enough’.

He was also defending his memoir after Buckingham Palace’s blistering statement that ‘the pain of fraternal grief can cloud reason, affect judgment and colour memory’.

Body language pro Judi James said the Earl repeatedly used a crucial ‘pinch’ gesture ‘between his index finger and thumb’ known as the ‘precision pinch’.

She told : ‘This is a gesture that implies accuracy of detail and he even uses it as a baton gesture at one point to appear to convey the message that he is being forensically accurate in what he says.’

He uses the motion when he is challenged about his claim that then Prince Charles was ‘giddily elated like a lottery winner’ after Diana’s car crash death in 1997.

Pinching his fingers, the Earl says: ‘Every word I report exactly as I saw it and felt it at the time’.

According to Judi James, another crucial body language tell the Earl uses it that he ‘tends to relate the events he writes about by partially “living” them.’

This includes miming picking up the phone when he talking about taking the two phone calls from Charles after Diana’s death.

The miming and ‘precision pinch’ gestures combine forces later in the interview when he is asked about his claim that Charles told him ‘Rest assured, we’ll forget her soon enough’ after a row over the funeral.

The Earl told Laura Kuenssberg: ‘After a stunned silence, I said you cannot believe you just said that, and I hang up on him.’

As he tells the BBC host that, Princess Diana’s brother pinches his fingers before imitating hanging up the phone with his hands.

James told : ‘His delivery of his conversations with Charles also comes with that style of reliving the incident, complete with an upwardly pointed index finger and the precision pinch gesture before he mimes hanging up the phone.’

The expert does stress that ‘body language cannot define between truth and lie.’

However she added: ‘But Spencer appears happy to “bare all” visually here in terms of his eye expression and open body posture.’

James also said his ‘over his display [in the interview] is generally congruent’.

She continued: ‘When he does show emotion openly as his eyes fill with tears at the thought of his happy childhood with Diana, the sadness does look authentic as we see close-up his eyes slowly redden and moisten and hear his voice crumble and break.’

The explosive interview also saw the Earl reveal that the revelations in his book ‘will not be a surprise’ to William and Harry.

He also recounted the night he got the call from his sister Lady Jane Fellowes, who said Princess Diana had been in a crash but ‘it’s not too serious’.

But as he looked for updates he got more distressing news from his sister.

‘And then my sister Jane said, “I’m afraid she’s died.” It started… as a little prang, and then it became a broken leg, perhaps a head injury, and then death.’

He explained Diana rang up her brother to tell him the reason she was getting divorced, telling him: ‘My husband is in love with his valet’.

‘I told her, “I do worry that the public will really be, in a way, angry with you for killing the fairy tale that they’ve all subscribed to”, and those are the words she said to me.’

Spencer even hinted there could be more Royal family secrets which have been ‘left unsaid.’

BBC’s Laura Kuenssberg asked him: ‘Maybe some family secrets are better left unsaid.’

He replied: ‘They certainly are, and they have been left unsaid.’

But will it be Earl Spencer who will spill the beans? He claims: ‘Nope, that’s it. That’s me done.’

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