Australian Shaun Davidson has escaped from his prison in Bali, Indonesia. The WA man, who was jailed in Kerobokan prison for using another man’s passport, is reportedly part of the four foreign escapees, which include a Bulgarian, Malaysian and an Indian prisoner.

According to reports, the four escapees – Davidson, Bulgarian Dimitar Nikolov Iliev, Indian Sayed Mohammed Said and Malaysian Tee Kok King – have used a small underground tunnel that is less than a metre wide to escape. The tunnel had a diameter of 50x75 cm and is about 12 metres long. Head of Kerobokan prison Tony Nainggolan said the inmates might have taken a week to build it. He also believed that the men were still in Bali.

He said the great escape is believed to have taken place on Sunday night when there were 10 guards on duty. As Reuters notes, prison escapes are fairly common in the Southeast Asian country. The notorious Kerobokan prison, which housed the infamous Australian Bali Nine inmates, has a capacity of 323 prisoners, but it currently houses more than four times at 1,378.

The four escapees were serving sentences for different crimes. Said, 31, had 12 years and three months to go for drug offences. Iliev, 43, was serving seven-year sentence for money laundering, while King, 50, had been serving seven and a half for drug offences as well.

Davidson, 33, who fled drug charges in Perth, spent a year in Bali before he was jailed for using fraudulent travel documents. He was arrested in April 2016 after he signed into a guest house in Kuta under the name Michael John Bayman from a passport. He claimed that his passport used a “chubby” photo of him.

He was sentenced to one year in prison and fined 100 million rupiah (AU$10,000), but he opted to serve extra five months instead of paying the fine. He had just two months and 15 days remaining on his sentence before his escape.