Robert De Niro attempted to steer Tom Sizemore away from drugs when he discovered the BLACK HAWK DOWN star was using heroin while they were shooting HEAT together in the mid-1990s.

The actor, who now attends daily meetings in a bid to stay clean and sober, reveals De Niro intervened on the set of Heat and insisted he check into rehab.

Sizemore, who has been hooked on crystal methamphetamine since 2001, recalls, "At the time I was using another drug... It starts with an H. I would take just enough to be not sick. I was completely within my faculties when I was working.

"It was after work (when I had) problems and Bob De Niro confronted me and I told the truth, and I went with him to this treatment centre in Arizona, and I got clean.

"He (De Niro) doesn't like confrontation. He said to me one day, 'I know what you're doing,' and I said, 'I'm not doing anything you're not doing,' and he went, 'Oh yes you are!'"