A Perth teenager who was held in Bali on suspicion of carrying drugs is now safely home in Australia after being cleared by a forensic analysis and released from a Kuta police station.

Teenager Jamie Murphy and his parents Brendan and Anna were whisked out of Perth airport with the assistance of staff via a private exit and in to a waiting van that raced off to avoid a press pack.

His arrival ends a tumultuous few days in which the 18 year old was physically roughed up by security while being filmed and faced the possibility of prison time, but was released when test results of both the powder and his urine came back negative for illegal drugs.

Having arrived in Bali on Sunday night with two friends celebrating graduation, the teenager was arrested at the nightclub Sky Garden just before 1am local time on Tuesday.

Kuta police chief Wayan Sumara told reporters the powder turned out to be a mixture of painkillers, caffeine, cold and flu medication and cough medication – not the heroin or cocaine originally suspected.

Mr Murphy had been facing up to 12 years prison after a bouncer allegedly confiscated the powder from him outside the Skygarden nightclub on Monday.

Mr Murphy’s lawyer Dessy Widiantari told reporters the test results had come back negative after visiting his client on Wednesday.

Jamie Murphy’s lawyer told media the results had come back negative. Photo: AAP

Mr Murphy’s friends yelled that he had been “set up” as police arrested him and took him to the Kuta police station, where he spent two nights.

Despite his friends’ insistence the drugs had been planted, Kuta Police Chief Commissioner Wayan Sumara told reporters the boy had admitted purchasing the substance.

“He said he got it from one of the people on the street,” Chief Sumara said after the arrest.

During Murphy’s arrest at the nightclub, Nine Network footage showed him protesting that the drugs were not his, adding: “It’s not mine, I haven’t taken it, what are you doing, it’s not mine. It’s not mine.”

“I don’t do this s***, I only drink,” he added.

Mr Murphy’s parents arrived in Denpasar on Wednesday from Perth, while friends delivered him food and beverages during his stay in custody.

The incident comes after the recent news that Schapelle Corby, who was convicted of possessing 4.2 kilograms of cannabis in 2005, was given a date for her return to Australia after a decade.

Last year a 26-year-old Australian man was jailed for 12 months for possessing one joint of cannabis, and in 2011 a 14-year-old Australian boy spent two months in detention after he was caught with a small amount of hashish.

-with AAP/ABC