LOS ANGELES — The Los Angeles County coroner’s department is investigating the death of rocker Tom Petty.

Department spokesman Ed Winter says an autopsy was conducted Tuesday but that further examination is needed to determine the exact cause of death.

Petty was 66 years old when he died Monday at a hospital. A spokeswoman said he went into cardiac arrest at his Malibu home.

No foul play is suspected, but Winter says the coroner investigates all deaths where the deceased hadn’t seen a doctor in six months.

Winter says results of toxicology screening — to determine whether Petty had any drugs in his system — could take several weeks.