Charles Spencer "barely spoke" to his sister Diana, Princess of Wales, during the final years of her life and was not there when she needed him, according to her former butler Paul Burrell.

The 62-year-old Earl Spencer has this week published Swan Song: Diana, My Sister, his highly publicised memoir about Diana, who died aged 36 in a car crash in Paris in 1997.

The book has already prompted an extraordinary dispute with Buckingham Palace over Charles' account of King Charles III's reaction to Diana's death and a threatened legal action from Piers Morgan over an acknowledged factual error.

Appearing on Piers Morgan Uncensored, Paul, 68, said of Charles and Diana's relationship: "They barely spoke. He was not part of her world."

Referring to Swan Song, Paul added: "I'd think those last five years... are pretty vague in the book because he knows nothing about them."

Paul, who worked for Diana and became one of her best-known members of staff, also recalled her complaining about her relationship with members of the Spencer family.

He quoted Diana as saying: "My family only want me when they want the best seats in the best restaurants or want to sit in the Royal Box at Wimbledon."

Paul's intervention comes as Charles promotes a memoir which he has described as his attempt to record his memories of his sister ahead of the 30th anniversary of her death.

The book covers Diana's childhood, marriage, divorce and death as well as the week leading to her funeral.

Siblings Charles and Diana had a documented disagreement over Diana's wish to live at Althorp, the Spencer family estate in Northamptonshire, following her separation from the then Prince Charles.

Charles has said security concerns prevented Diana from moving into Garden House because of its proximity to a public road, and has maintained that other properties on the estate were offered to her.

The relationship between Charles and the royal family has returned to the centre of public attention because of claims in Swan Song about the aftermath of Diana's death.

Charles alleges the now King Charles III, 77, told him: "Rest assured, we'll forget her soon enough" during a heated telephone conversation about Diana's funeral arrangements.

He has also described the-then Prince of Wales as sounding "giddily elated" in the wake of her death.

Buckingham Palace has disputed Charles's account, saying: "The pain of fraternal grief can cloud reason, affect judgment and colour memory in ways others do not recognise."

Charles has stood by his recollection, telling the BBC: "Those are exactly the words he said."

He subsequently accused Buckingham Palace of "gaslighting" him over its response and insisted he had not intended the memoir to be a "hit piece on the King".

Paul has now publicly challenged Charles's description of the King's behaviour after Diana's death, saying he witnessed Charles after he arrived in Paris.

Paul said: "He was a broken man. He was devastated."

He added: "He went into the room with Diana's sisters for 10 minutes and came out. Clearly, he'd been crying. His eyes were bloodshot. And honestly, I've never seen him like that, ever. He was pale and he was scared."

The controversy surrounding Swan Song widened after Piers Morgan challenged a passage concerning intrusive photographs taken of Diana exercising at a gym in 1993.

Charles' book incorrectly linked Piers to the Sunday Mirror at the time the photographs were published.

Piers was then working at the Sun and did not join the Mirror until 1995.

Charles subsequently apologised for what he called an "incorrect assumption".

Piers has said he nevertheless intends to pursue legal action against Charles and the book's publisher, Penguin, and has questioned the reliability of other passages in the memoir.