Former Playboy Bunnies Holly Madison and Bridget Marquardt revealed pictures of the playmates' genital area used to be auctioned off in a grim 'brown book'.
The duo discussed the dark side of Hugh Hefner's gigantic empire on their Girls Next Level podcast and opened up about the secret book.
Holly started dating the tycoon in 2001 when she was only 21 years old while Bridget was 28.
According to Holly, the camera crew used to try to catch "upskirt" shots of the models when they were filming for The Girls Next Door series.
The series focused on the lives of Hugh's girlfriends who lived with him at the Playboy Mansion.
Playboy model found strangled to death in bed after 'most gruesome' murderIn one scene of the show, cameras captured Holly's private parts when she jumped onto the sofa.
"I didn't think there was anything wrong with you diving on the couch and you not care, but I don't know why they had to keep that in, why couldn't they have panned," Bridget pondered.
There was one shot from the show that features an upskirt shot of fellow Playmate Kendra.
Thankfully, they "airbrushed out my p****".
She said: "There was a shot in one of the limo pictures and you could see A LOT."
Although areas were airbrushed out of the show, Hugh had photos of the original un-touched version in a secret "brown book" that he would sell off.
"It's another example of, in the Playboy world, nudity is taken for granted," Holly said.
According to the former playmate, Hugh - who died in 2017 - also kept a record of when the models used money and "who slept with him and when".
Holly claimed that the Playboy founder "planned on selling [a secret book of X-rated images of the playmates] to a library".
"So that was another thing that made me feel kind of weird and afraid to leave, ‘cause I felt like there was this mountain of revenge porn," she continued.
Pamela Anderson's childhood dream job was to be a nun before Playboy stardomHolly dated the Playboy founder from 2001 to 2008.
Over the years, former playmates have opened up about the dark side of living in the Playboy Mansion, which includes 'gross' sex with Hugh, being blacklisted, and strict routines.