Britney Spears‘ ex bodyguard Tony Barretto says he saw her using drugs on two occasions after she left rehab, both times in a nightclub in Los Angeles. “One was at her table. She had me hold up a curtain to make her area private,” he told Matt Lauer on the Today show Monday. “At one point it was getting kind of hard to continue to hold the curtain for such a long period of time. The attempt was to look over and get her approval to let go of the curtain, at which point, I noticed what she was doing.”

Barretto said the second incident was at the same Los Angeles club. “The other occasion, we escorted her to a private rest room upstairs that was secured for her. She was in there for some time alone, and I was waiting for her outside the door. I thought it would be appropriate to check on her, and I knocked and peeked in and I observed this behavior.”

In an interview with Britain’s News of the World, Barretto says the scariest night he experienced with Brit was on May 2 at the Mondrian Hotel in L.A. He says Spears was hysterical after some pre-concert partying with rocker Howie Day. According to Barretto, the room was full of empty mini-bottles and “on the surface of the dresser, I could see mounds of white powder and a straw on top. I suspect it was cocaine or methamphetamines.”

He added, “She was in a terrible state, just sweating and shaking. Her pupils were huge — I’ve never seen her so bad.”

Barretto — who was identified the “secret witness” whose testimony last week pushed a Los Angeles judge to order random drug testing for Britney — says he is speaking out in an effort to help her two sons. “This is a wake up call. Get help,” the bodyguard urged in his News of the World interview. “Think of the kids.”