A shocking video has been released that proves why Charlie Sheen's ex Brooke Mueller is currently in rehab and lost custody of their two sons.

Radar Online posted a video of Mueller smoking crack cocaine out of a glass pipe and purchasing $1,500 worth of crystal meth.

In the shocking photos and video, the Palm Beach socialite --who is currently in rehab for the 20th time-- is wide-eyed and looking somber while holding a glass pipe. The footage was filmed before she began treatment in May.

In the short video clip, Mueller holds the glass pipe to her lips, then lights the crack, a cocaine derivative, then inhales it. She is then heard in the footage asking the drug dealer for crystal meth.

"Where is the crystal? I am giving you $1500," she says repeatedly.

View the shocking photos of Brooke Mueller smoking crack here.

Watch the 36-second clip of her smoking out of the glass pipe here.

The source who supplied the video to Radar Online said they are doing so to help the fallen former model. They are hoping it will help her decide to stop using drugs for good. The insider said Mueller did drugs at least three or four times a week

"Brooke loved getting high," the source told RadarOnline. "This was just another crazy night of her getting high. When she did drugs, it was three to four times a week. I know that she is aware that if she doesn't stop doing drugs, she is going to lose her kids (for good)... hopefully she can stop."

Sheen's two boys are currently living with Sheen's other ex-wife and mother of his two daughters, Denise Richards. She gained temporary custody in May after Meuller was placed in an involuntary psychiatric hold. Child services determined she could not provide for her children at the time.

Denise Richards Taking Care Of Charlie Sheen's Twins While Brooke Mueller In Rehab

TMZ reported in July that Mueller can possibly get her children in the next six months to a year if she follows certain conditions that prove she can maintain sobriety.

Tags: Charlie Sheen Brooke Mueller