A 2002 article published by The Guardian confirmed that Princess Diana possessed a tape (that is now missing) consisting of the testimony of a victim who had been raped in the palace. This could be the source from which Anonymous based their revelations off of.
Anonymous tweeted, “Around the time of her death, Diana was visiting hospitals and care homes Jimmy Savile was preying on at all hours of the night, consoled Elm Guest House victims, and recorded palace rape victim testimony.”
Jimmy Savile was an English media personality who, during his lifetime, was well known in the UK for his outlandish personality and was generally respected for his charitable work. He was actually knighted in 1990. In late 2012, almost a year after his death, reports surfaced that Savile had sexually abused hundreds of individuals throughout his life, with alleged male and female victims, ranging from children to adults.