Ke$ha's advisor reportedly encouraged her to "shove her hand down her throat".
The popstar is currently being treated in rehab for anorexia and bulimia, which is partially alleged to be down to the pressure music producer Dr. Luke put on her to stay skinny.
Now her mother Pebe Sebert claims another member of her entourage was putting the heat on the singer to lose weight, even encouraging dangerous methods.
"It wasn't just Luke. She had an advisor who told her he had a meeting with a record company and they said she better lose 15lbs. in the next 30 days," Pebe told RadarOnline.
"He told her he didn't care if she shoved her hand down her throat or took illegal drugs, but she had to lose the weight.
"Everybody in the industry has thrown up! Ke$ha's been in the bathroom with other celebrities throwing up!
"Who knows who's the one who's gonna have the heart attack or the stroke? She was really good at hiding it."
Ke$ha signed with Dr. Luke in 2005, but struck up a new deal with RCA Records in 2009.
When she first started out, Pebe says the producer put a lot of pressure on her to look a certain way.
"She had been dieting and exercising and she got really thin and Luke told her she wasn't thin enough and needed a trainer, but I couldn't afford a trainer as a single mom. She came home a month or two later so skinny," she said.
"She told me she was juicing and hiking Runyon, but she was throwing up. I knew at some point she'd done it. I told her it was dangerous… her teeth, her voice. She'd swear she wasn't doing it anymore, but had a breakdown right before Christmas and told me she'd been doing it pretty much on a daily basis since two months after she signed with Luke."
It was rumoured alcohol was also behind Ke$ha's rehab stint, but her mother has dismissed these claims.