Black Sabbath use to have cocaine flown in to them by ''private plane''.

The heavy metal band reunited its original line up - Ozzy Osbourne, Bill Ward, Tony Iommi and Geezer Butler - in November 2011 and the quartet admit their 70s heydays were out of control because they became so reliant on drugs.

Tony - who almost overdosed one night at the Hollywood Bowl - told The Guardian newspaper: ''We were young blokes, doing what young blokes do. I was doing coke left, right and centre, and quaaludes, and God knows what else. We used to have [cocaine] flown in by private plane.''

Ozzy - whose heavy drug use led to his dismissal from the band in 1979 - was frequently going walkabout and would end up drinking until he found himself in a police cell blacked out.

Geezer explained: ''You can't write or play songs if you're out of your brains. But because [Ozzy] didn't have to play an instrument, while we were writing he'd be in the bar getting legless or doing all kinds of things.''

Ozzy added: ''I didn't believe it when they said I had blackouts. I'd look at my watch and it would say four o'clock. Then I'd look again and it would say 9.30. I'd totally forget where I'd been or what I'd done.

''But then you don't think about that before you start drinking. You don't think: 'I wonder what jail I'll wake up in tomorrow?' Because that's not your intention.''

The band are set to release their first album together in 33 years, '13', but initially had to put their plans on hold after Tony was diagnosed with cancer, causing them to relocate from the US to the UK while he received treatment .

Tony insists: ''I'm not so bad. The treatment is ongoing.''

'13' is out on June 10.