Rudy Eugene was not high on bath salts when he launched his naked ‘cannibal’ attack on a homeless man, a medical examiner revealed last week.

The only drug found in 31-year-old’s system was cannabis, leading examiners to believe that Eugene, who had a history of mental illness, may have been experiencing marijuana-induced psychosis when he carried out his savage attack on 65-year-old Ronald Poppo.

Miami’s Local10 news website reported that Eugene, who was shot and killed by police during the attack on Miami’s MacArthur Causeway, had been diagnosed with schizophrenia after a previous arrest.

Authorities were unclear if he had ever sought treatment for the illness, but his family confirmed he was a regular cannabis user.

The Miami Herald previously reported that court records revealed Eugene had married in December 2005, but divorced just over two years later.

“I wouldn’t say he had mental problems but he always felt like people was against him... No one was for him, everyone was against him,” his ex-wife told Miami-based television station WPLG in the immediate aftermath of the attack.

The Miami Herald also reported that Eugene had previously been arrested on a battery charge when he was 16, but that charge was later dropped. He was arrested seven more times over the next five years; four times for marijuana offences, once for misdemeanor battery, once for vending near a school, and once for trespassing.

Poppo sustained horrific injuries during the attack, which took place in May this year. Eugene chewed off up to 80 per cent of Poppo’s face, leaving him with wounds described by hospital workers as "some of the worst staff had ever encountered." Poppo remains in hospital.

Police were initially called to reports of two naked men fighting on the MacArthur Causeway bike path, which was packed with people heading to the annual Memorial Day hip hop festival. After he refused to end the attack, police fatally shot Eugene.

Much of the attack was caught on the CCTV cameras of the office building that houses the Miami Herald newspaper. The images went viral in the immediate aftermath of the attack.

The British Medical Journal last year published a 10-year study into cannabis and found that use increased the risk of ‘incident psychotic experiences’.