Although singer-songwriter Elton John was friends with the late pop icon Michael Jackson, he has made some startling revelations about the latter including that he was "mentally ill", in his memoir titled 'Me'.
"I'd known Michael since he was 13 or 14. 

He was just the most adorable kid you could imagine. But at some point in the intervening years, he started sequestering himself away from the world, and away from reality the way Elvis Presley did," John wrote in an excerpt from 'Me', published by The Independent and cited by People. John added that every time he came across the singer, he would think that Jackson "had totally lost his marbles."

"I don't mean that in a light-hearted way. He was genuinely mentally ill, a disturbing person to be around," he added writing that it was incredibly sad.

Penning his memoir, John recalled the time of a dinner party thrown by him and Jackson as his invitee who would eat anything and even dismissed himself from the table.

Later, the pop icon was found with the housekeeper and her 11-year old kid.

"For whatever reason, he couldn't seem to cope with an adult company at all," John wrote in his memoir.

Jackson has been in headlines of late due to his HBO documentary 'Leaving Neverland' which features two people claiming that the late singer sexually abused them as children.

The star, who died in June 2009, had repeatedly denied any wrongdoing prior to his death.

In 2005, he was acquitted in a child sex abuse case leveled against him in California.