Disney star, Demi Lovato's recent meltdown was caused by heavy drug and alcohol abuse, not the eating disorders previously reported according to the latest source.

“Demi’s been on a tear lately. She’ll chug booze straight from the bottle,” a source told Life & Style.

Last week the 18-year-old star checked into an Illinois rehab clinic citing “physical and emotional issues.”

Brian Payne, a Texan college student who claims he spent a night partying with Demi said the star was snorting cocaine.

He told Life & Style that she did “line after line like a pro. I remember her doing it as if she had been doing it for a long time.”

Yesterday reports from Radaronline.com said that a video of Demi snorting drugs is being circulated among media outlets.

However reps for the troubled actress have categorically denied the allegations.

"Demi Lovato is not in treatment for drug or alcohol addiction. As we have said since she entered treatment last week, Demi decided to seek help for emotional and physical issues she has battled throughout her life," her reps, Tiffany Shipp and Jesse Derris, said in a statement.

"She has taken this step in order to get her life in order," they added.