George Michael’s music career and his health is under threat because of a cannabis addiction, a colleague claims.

Toby Bourke, who sang with Michael on the song, Waltz Away Dreaming, says the singer has become a “stoned waster” and smokes 20 joints a day.

He told the Daily Mirror, “Drugs have turned him into a stoned waster and made him depressed.

“Dope destroyed his will to work. When you smoke as much as George has done you simply cease to function.

“Cannabis has wrecked his career. He is basically lazy, and it is all the cannabis he’s smoked that has made him like that.”

The gay star has been questioned “under caution” by police over allegations he hit three parked cars before driving off without leaving any details, on Sunday morning.

He is still expected to appear in an interview on ITV’s Parkinson show this weekend.