Rock singer Scott Weiland's death in a tour bus in a Minneapolis suburb on Dec 3 resulted from the toxic effects of a mixture of drugs including cocaine and ecstasy with alcohol, and has been deemed an accident, a county medical examiner said on Friday.

Weiland, 48, the former front man for the band Stone Temple Pilots, was touring with his new band, the Wildabouts, when he died in his sleep in Bloomington, Minnesota. Police said at the time they had recovered a small amount of cocaine from the band's tour bus.

The Hennepin County Medical Examiner said Weiland's accidental death was caused by mixed drug toxicity but also noted that the California-born singer had heart disease, a history of asthma and "multi-substance dependence."

Weiland had acknowledged a long history of cocaine and heroin abuse.

He co-founded Stone Temple Pilots, also known as STP, in the late 1980s. The band was known for its guitar-heavy hits "Plush" in 1993 and "Interstate Love Song" the following year. It broke up in 2003 and reunited five years later only to collapse in acrimony again in 2013 when bandmates forced Weiland out for what their attorney called "destructive behavior."

He performed with the group Velvet Revolver for a number of years and the Wildabouts released their debut album this year.