SAN FRANCISCO (AFP) - The sudden death of prominent hacker Barnaby Jack was due to an accidental overdose of heroin, cocaine and other drugs, a coroner's report said on Friday.

The New Zealand-born Mr Jack, 36, a software wizard famous for remotely hacking ATMs and medical devices, was found dead in his bed by his girlfriend in July.

An autopsy found "no visible or palpable evidence of trauma" on the body.

There was "blood inside the nostrils" and "sparse white foam inside the mouth", the report from the San Francisco Medical Examiner's office said.

A toxicology screen found evidence of "acute mixed drug ... intoxication" from heroin, cocaine, the antihistamine diphenhydramine and Xanax, which combined to cause Mr Jack's death, the medical examiner said.

The New Zealand native and San Francisco resident worked as a software security researcher at IOActive Labs.

An admired member of the hacker community, Mr Jack said in an IOActive blog post months before his death he had been spending the majority of his time researching vulnerabilities in new model wireless pacemakers and Implantable Cardioverter Defibrillators (ICDs).

Three years earlier, Mr Jack demonstrated his "ATM jackpotting" discovery for an overflow crowd of hackers during a presentation at the infamous DefCon hacker gathering held on the heels of Black Hat annually in Las Vegas.

Mr Jack found a way to access ATMs remotely using the Internet. Once in the machines, he could command them to spit out cash or transfer funds.

He didn't reveal specifics of the attack to hackers even though the ATM makers were told of the flaw and have bolstered machine defenses.

He was admired by his fellow hackers, who took to Twitter last year after his sudden death to pay tribute.

"Lost but never forgotten our beloved pirate, Barnaby Jack has passed," IOActive said in a message at the company's Twitter account.

"He was a master hacker and dear friend. Here's to you Barnes!"