(EDGE) As part of a documentary marking the 20th anniversary of Princess Diana's death, Elton John is praising the late icon's work as an AIDS activist and with the LGBT community, The Daily Mail reports.

In a conversation with Diana's son Prince Harry, 32, John is opening up about his close friend's legacy and death. Harry joined the pop star at the London Lighthouse AIDS Centre where they discussed her groundbreaking work. 

"It was considered to be a gay disease and for someone who was in the royal family and who was a woman and who was straight, to have someone care from the other side was an incredible gift," John explained. As the men look at photos of Diana spending time with AIDS patients, John adds, "Look at her face in every photograph, there is a positive wonderful glow."

"She had this incredible ability which he (Harry) kind of inherited, to make people feel at ease and make them feel that everything is going to be alright," the singer goes on to say. "I haven't experienced many people in my life who have that ability. She could walk into a room of people and make them feel as if everything was great." 

Watch the heartwarming clip below.