LOS ANGELES (Reuters) - Rock-and-roll pioneer Ike Turner died of a cocaine overdose, the San Diego County medical examiner said on Wednesday.

Turner, 76, was found dead on December 12 at his home in San Marcos near San Diego. He had a history of cocaine addiction stretching back more than 30 years.

The medical examiner said an autopsy showed that a long history of cardiovascular disease and emphysema contributed to Turner's death.

Turner was considered one of the founding fathers of rock music but his run-ins with the law and a messy marriage to R&B singer Tina Turner shadowed his musical accomplishments.

His "Rocket 88" with the Kings of Rhythm is credited with helping to change the look of rock and roll in the 1950s and his fame grew over the next two decades.

He married Tina in 1958 and by 1972 they had won a Grammy for their cover of "Proud Mary".

After Tina divorced him in 1976 because of his violent and abusive manner, Turner soon turned to a life of drugs.

His addiction to cocaine drained his finances and led to several arrests, most of which were drug related. Turner could not attend his own Rock n' Roll Hall of Fame induction because he was serving a prison term.

Turner won his second Grammy in early 2007 for "Risin' with the Blues".