Denzel Washington never drinks while he's acting.

The 58-year-old actor plays a drunk, drug taking pilot in 'Flight' but would never actually consume alcohol before filming any scenes in a movie after a bad experience when he was younger.

He said: ''I did a movie in London in the 80s, 'For Queen and Country', and there was a scene where we had to drink. So me and this other young actor said: 'Man, let's really drink.' We had some scotch and thought we were playing it pretty cool. And the director said: 'What's wrong with you guys?'

''We thought we were wild but we were really just dull. The director was p***ed off and it taught me a lesson. That was the last time I ever drank while working. Because it doesn't work. I've worked with actors who've crossed that line and it's just not worth it. You think you're giving 100 per cent, but all the while your level is dropping.''

The star has had a distinguished career, picking up two Oscars - Best Supporting Actor for 'Glory' in 1989 and Best Actor for 'Training Day' in 2001 - and says he was drawn to acting ever since he was a child.

He added to The Guardian newspaper: ''Acting was my calling. The year I started acting there was a woman in my mother's beauty shop, a kind of seer if you like, who kept looking at me in the mirror.

''Finally she got a piece of paper and wrote 'prophecy' at the top. She said: 'You are going to travel the world and preach to millions of people.' Now, bear in mind that I'd just been kicked out of school. I said: 'You see anything there about me being let back into school?'. That was March 75 and September 75 I started acting. I still got that piece of paper too.''