An 18-year-old Kiwi says he was shaved, held in solitary confinement and locked in a crowded Thai prison after being arrested for pocketing a watch at airport security.

Loukas Rainger, who has just been released on bail and reunited with his mum after spending six days in the high-security Surat Thani Prison, is now recovering from the “nightmare” ordeal.

“There were no beds – just a single blanket on the hard floor – and I had to wash out of a bucket right in front of 20 other guys,” he told Stuff.

He remains in Surat Thani awaiting a September 4 trial on a theft charge, which he denies.

While he accepted he picked up the watch, he denied intending to steal it, saying he was confused and not thinking straight at the time, he told Stuff.

Rainger was travelling through Surat Thani airport in July during his OE when he picked up a watch that had been left in a luggage tray at security.

He continued his holiday for two weeks before being stopped by immigration at Suvarnabhumi Airport in Bangkok last Thursday as he attempted to fly home to New Zealand.

“They told me there was an arrest warrant for airport theft,” Rainger told Stuff. “I wasn’t even worried at first because I simply thought, oh, they must have got me mixed up with someone else.”

A Tauranga teenager accused of stealing a watch from a Thai airport has described the “nightmare” conditions he endured during six days in prison as he awaits trial. Photo / Natasha Rainger

He was detained in Bangkok, bundled into a train and handcuffed for a 10-hour ride back to Surat Thani – the place where he took the watch.

“That’s where the real nightmare kicked in,” Rainger told Stuff. “They shaved my head and threw me into a cell with 20 men – real criminals and gang members. Honestly, when they found out my alleged crime was over a watch and saw how young I was, they all just laughed.”

Rainger said once he was released he had lost 10kg.

“In the heat of the cell, and all the bodies, sweat and our bucket there… I didn’t feel like eating," he told Stuff.

He was charged with “theft at an airport,” a serious offence in Thailand that carries a maximum prison sentence of five years.

“I’m not broken by this, but it’s definitely opened my eyes to the world fast,” he told the outlet, later saying, “We just want to go home.”

Loukas Rainger is in Surat Thani prison. Photo / Givealittle

Rainger was released on bail after a payment of 100,000 Thai baht (approximately $5000). He has been reunited with his mother, who was already in Bangkok for surgery at the time of his arrest.

Under his bail conditions, Rainger must remain in Thailand, live near the prison, and check in with authorities every two weeks.

His family has launched a Givealittle page to help with the ongoing costs of legal fees, accommodation, and living expenses while they await the court proceedings.