Rebel Wilson claims she was once invited to a "drug-fuelled orgy" by a member of the British royal family.
In her new memoir Rebel Rising, the Pitch Perfect star detailed the alleged incident, saying it had unfolded in 2014 at a US tech billionaire's house, the Telegraph newspaper said.
"I got thrown a last-minute invite to a tech billionaire's party - the guy who invited me, who's like fifteenth or twentieth in line to the British throne, had said to my male friend, 'We need more girls'," Wilson claimed.
She did not identify the royal.
She said the medieval-themed event took place at a ranch outside Los Angeles.
"The party was insane. Men were jousting on horses in a field, girls dressed as mermaids were in the pool. The property was massive, and because it was quite a drive, people had been assigned rooms to sleep there overnight.
"There's a huge private fireworks display and then all of a sudden it's 2am and a guy comes out with a large tray piled with what looks like a tonne of candy.
"I'm like, 'Ooooh, is that candy?' and the guy holding the tray says, 'No, this is the molly [MDMA],' and I turned to the screenwriter I've been talking with, confused. He says, 'Oh, it's for the orgy - the orgies normally start at these things about this time'," she wrote.
The claim is the latest in a line of controversial revelations from the memoir.
Recent headlines around the book have focused on her belief singer Adele "hates" her because people have gotten them confused for one another and details of her loss of virginity at the age of 35 with actor Mickey Gooch Jr.
The most sensational claim from the book involved Ali G actor Sacha Baron Cohen.
At the end of March, the Bridesmaids actor claimed Sacha Baron Cohen had tried to stop the release of the book after she named an "a**hole" who had caused her problems.
Wilson and Baron Cohen starred together in The Brothers Grimsby in 2016.
"I will not be bullied or silenced with high priced lawyer or PR crisis managers," Wilson wrote on her Instagram stories on Monday.
"The 'a**hole' that I am talking about in ONE CHAPTER of my book is Sacha Baron Cohen."
In the days following the furore, Cohen and wife Isla Fisher subsequently revealed they were divorcing after 13 years together.
