Princess Diana's former bodyguard has revealed his belief that she would still be alive today if she hadn't given up her security detail after divorcing Prince Charles.
In a TV interview he recalls the advice he gave the royal, saying: "Whatever you want to do, you will always be Diana, the Princess of Wales. The one thing that you shouldn't give up is your security. I urge you strongly not to do that.
He added: "There's only one person that could - in my view - that could have insisted that she retain her security, and that would have been the queen herself.
"If the queen had insisted that she retain that security then we wouldn't be having this discussion because Diana, in my view, would have been alive today."
Wharfe, a Metropolitan Police protection officer, makes the remarks in a two-hour programme airing this Friday The Life and Death of Princess Diana: A Dateline Investigation.
The show also features James Colthurst, a close confidante of Diana's, who says she was also fearful of being sidelined by Charles' relationship with Camilla, the Daily Mail reports.
"Her big fear was that this is not a substitute mother for the boys. That they would try to sideline Diana and that Camilla might use her post," he explains.
The programme will examine Diana's troubled marriage to Prince Charles, her subsequent love affairs and her tragic death and the investigation that followed.
Paris police chief Martine Monteil, forensic scientist Patrick Touron and former French diplomat Sami Nair, will be interviewed about the aftermath of her death.
Diana's friend Simone Simmons, lead UK investigator Lord John Stevens, photographer Pierre Suu and reporter Richard Kay will also provide insights.
Back in August 1997 Princess Diana was staying in Paris with her then boyfriend, Dodi Fayed, following a summer holiday to the South of France, while her children were with the Queen at Balmoral.
The couple had taken up residence in a suite at the Ritz, owned by Dodi's father, Mohamed Al Fayed, when they were killed in a car driven by the hotel's acting head of security, Henri Paul, who an inquest later found to be drunk and speeding as they entered the Alma Tunnel.
The inquest found he had lost control of the car and crashed into a pillar, killing himself, Diana and Dodi. Only Dodi's bodyguard survived.
Today it was revealed that Princess William and Harry will share intimate memories of their mother in another upcoming documentary to mark the 20th anniversary of her death.
The pair will speak openly about how her influence shaped their lives in the Oxford Films produced programme, as well as her charity and humanitarian work in many fields, including landmines, HIV and homelessness in a documentary, which will air on HBO in the US and ITV in the UK.
ITV's Jo Clinton-Davis, Controller of Factual, said the film would shed new light on Diana's life through rare insight from her son's and friends who have been before been interviewed.
"This new ITV film will offer viewers a fresh and revealing insight into Princess Diana through the personal and intimate reflections of her two sons and of her friends and family, many of whom have never spoken before, to bring together a definitive portrait of a unique person who touched the lives of millions," she explained.