Indonesian police have launched a search for an Australian man and three other foreigners believed to have escaped from Kerobokan prison in Bali through a 15-metre tunnel.

Shaun Davidson, 33, from Perth was sentenced to one year in Kerobokan last September for immigration offences after he used another man’s passport.

Kuta police said Davidson was among the group alleged to have made the brazen escape sometime on Monday morning through a tunnel found behind the jail’s medical clinic.

The “hole”, police said, was around 50cm by 75cm wide and 15 metres long and travels underneath the prison wall and emerges at a road alongside Kerobokan.

The tunnel hole outside the prison walls through which Davidson and three others are said to have escaped. Photograph: Putra Sinulingga/AAP

Davidson’s photograph, along with those of his three fellow escapees, has been circulated around Bali as police attempt to find the men.



All the men were serving time in Kerobokan’s Bedugul block.



Dimitar Nikolov Iliev, 43, from Bulgaria was serving a seven-year term for money laundering, alleged fellow escapee Saye Mohammed Said – a 31-year-old from India – was in the midst of a 14-year sentence for drugs.



Malaysian man, Tee Kok King, 50, is understood to be serving seven and a half years for drug offences.



Davidson had just two months and 15 days left of his sentence to serve, at which point he would have faced deportation. There is a warrant for his arrest over drug offences in Perth.

When the 33-year-old arrived in Bali in January 2015 he said he spent several months just “partying and boxing” before arousing the suspicion of authorities when he signed into a guest house in Kuta under a passport with the name Michael John Bayman – claiming the photo was taken when he was “chubby”.



After his sentencing at Denpasar court last year, Davidson told AAP how he spent his first few weeks in custody crammed into a small cell with 20 other people.



“It was built for 300 people, there is 1,200 there ... It’s pretty hard for some of the locals in there, if they don’t have any money, you don’t eat. They don’t give you any food, they don’t give you a bed. They don’t give you anything.”



Although his sentence was only for one year, he opted to spend an an extra five months in prison rather than pay the 10 million rupiah fine ($A10,000).



Despite overcrowding in Kerobokan, he said it wasn’t the “living hell” he thought it would be.



“I guess I’m just lucky enough to have support from the outside,” he said.



Prison escapes in Indonesia are not unusual.

Last week 76 inmates escaped Jambi jail in Sumatra after flooding caused the prison’s walls to collapse.

In May, in another Sumatran facility, Pekanbaru, 442 prisoners made a run for it following allegations of guards charging people for cells in the chronically overcrowded facility.



In January 2013 there were reports of a prisoner escaping through Kerobokan’s sewerage system in the early hours. He was captured that night at his wife’s house.