Singer Elton John says Prince Harry inherited late Princess Diana's "incredible" gift of making people feel everything was going to be alright.

In the upcoming documentary, "Diana, Our Mother: Her Life and Legacy", friends, family and admirers of the late royal speak candidly about her charitable efforts.

John says that her efforts to promote HIV and AIDS awareness live on through her son, reports

"She had that incredible ability - which (Harry) kind of inherited - to make people feel at ease and make them feel that everything's gonna be all right," John, 70, said in the documentary. 

"I haven't experienced many people in my life who have that ability, but she could walk into a room of people and make them feel as if everything was great," he added.

Diana was a campaigner for HIV and AIDS awareness and treatment. And, along with John, the documentary features appearances by Diana's brother Charles Spencer and singer Rihanna, who took an HIV test alongside Prince Harry in Barbados last December to help break the stigma of getting tested.

In recent years, Harry has championed the fight against the illness. In March, he travelled to Leicester to visit the Leicestershire Aids Support Service, the organisation his mother visited just 25 years earlier.

In 2015, Harry, 32, founded the Mamohato Children's Centre in Lesotho, Africa, for children affected by the life-threatening virus. He honoured Lady Di’s memory by naming one of the orphanage’s dining halls after her.

"It's equally important, if not more so, to do the stuff behind the scenes. It's something that our mother did a lot,” the handsome redhead has said of his and Prince William’s philanthropic mum, whose life was cut short at the age of 36 in a fatal Paris car crash nearly 20 years ago. “And that's the time you really get to learn. You get the experiences and you actually get the honest truth out of people.”