DISNEY'S POP PRINCESS DEMI LOVATO IS IN REHAB FOR BEING A COKEHEAD!

Disney teen darling Demi Lovato was boozing and snorting cocaine like a rock star before she checked into a treatment center last week, a bombshell report reveals.
"She was doing line after line like a pro - and she was 17 at the time," Texas college student Brian Payne told Life & Style magazine, on newsstands Wednesday.

The 18-year-old Lovato's hard partying apparently continued right up to the point she checked into a treatment center last week, the magazine reports.

"Demi's been on a tear lately. She'll chug booze straight from the bottle," an unnamed source close to Lovato told the glossy.

The "Camp Rock" star's representatives have been vague about her hangups, saying she's getting medical treatment for "physical and emotional" issues.

Payne told Life & Style he witnessed the Disney Channel star snorting cocaine during a wild night of partying last December.

"I just remember her doing it [cocaine] as if she had been doing it for a long time," Payne said. "It didn't seem like something new to her."

Payne said he and the "Sunny With A Chance" star partied all night at the North Richmond Hills, Tex., house of a friend following a concert in Dallas.

He said Lovato ended up getting cozy with their host, a friend named Dave who was later killed in a water sport accident.

Friends told the magazine the untimely death and her breakup with Joe Jonas, 21, left Lovato heartbroken and fueled her heavy drinking.

"Since Joe dumped her, Demi's been depressed and drinking a lot. It's been hard for her to keep working so closely with Joe," another unnamed source told Life & Style.