Bali prison escapee Shaun Davidson only had two months left in jail

Australian Shaun Edward Davidson, 31, was among the escapees. Photo/News Corp Australia

Bali escapee Shaun Davidson tunnelled out of Kerobokan to avoid certain deportation back to Australian prison, but the Australian risks a "Death Island" cell if caught.

Davidson, 33, escaped with three other men down a narrow, 15m long tunnel from Bali's Kerobokan jail on Monday just two months and 15 days short of his release.

But Davidson, who had fled Perth on a false passport while on bail for alleged drug offences, would have been immediately deported after being freed and returned to Australian custody.

As Balinese police search for Davidson and three fellow escapees who may have already fled the island on a boat, there is speculation that he could be in another country.

All Indonesian airports and departure gates are on alert for the four escapees.

But Davidson, who has shown a capacity to evade authorities, may have fled through Indonesia's porous borders, vanishing by boat to other islands.

Indonesian law expert Professor Tim Lindsey told news.com.au that just like drug dealer Schapelle Corby last month, Davidson would have been detained on walking from Kerobokan.

Davidson was serving a 12 month sentence for having a passport in another man's name, the document on which he is believed to have left Australia.

"He would have been arrested on the spot for not having a valid visa and perhaps held in an immigration centre before being taken to the airport and put on a plane for Australia," Prof Lindsey said.

"But if he does get caught it's not considered an offence to escape, just a misdemeanour for which he would face disciplinary action by prison authorities.

"He could be in Thailand by now."

However, if recaptured, Davidson would serve the rest of his sentence and on release be sent back to Perth.

Due to a current outstanding warrant for his arrest in Western Australia, he would be taken into custody on arrival.

Davidson is believed to have travelled to Indonesia on January 28, 2015, the day he was due in Perth Magistrates Court charged with possession of drugs with intent to sell or supply.

Davidson spent the year "partying and boxing" in Bali before officials arrested him at a Kuta Beach guesthouse.

He declared the photo on the passport, which was in the name Michael John Bayman, was him when he had been "chubby".

A court sentenced Davidson to a year's prison plus a $10,000 fine, which he chose not to pay in exchange for a further five months in Kerobokan.

Davidson's apparent ability to skip the country and elude authorities until they finally caught up with him in Bali suggests he might further outrun the law.

Shaun Davidson could have taken a motor boat to another island and even vanish to the Philippines if he had money and contacts. Photo/Facebook

Apart from the false passport in the name of Michael John Bayman, Davison also had another alias, Eddie Lonsdale.

"He has already shown a capacity to get false documents, and he managed to live in Bali for a year before he was caught," an Indonesia observer who asked not to named told news.com.au.

"He could have hopped on a motor boat in Bali and by the end of the day be on another island.

"If he had money, he could find himself in the Philippines.

"If you're in prison in Bali, it's easy to have contact with people on the outside.

"If it's been organised in advance, he hops onto to a speed boat in a fishing village and he vanishes.

"There are many islands to go to in Indonesia's archipelago and he's not going to stick out in Bali, where a million Australians visit each year."

Prof Lindsey said that if Davidson is recaptured, he would lose remissions and privileges and face disciplinary action, but not do any further jail time.

He said it was "unlikely" that the escapee would sent to serve out the rest of their terms at a higher security prison, like the feared Nuskambangan or "death" island.

Jailbreaks are not uncommon in Indonesia, where prisons are overcrowded.

Kerobokan, which has an official capacity of 323 inmates, but currently houses more than four times that number at 1378.

Prison officers estimate it would have taken days to dig the escape route to an existing water drainage tunnel used by Davidson and his fellow escapees.

They are Bulgarian money launderer Dimitar Nikolov Iliev, 43, and Malaysian drug offender Tee Kok King, 50, both serving seven years, and Indian drug dealer Sayed Mohammed Said, 31, serving 14 years.

A cable to the jail's CCTV cameras in the area of the escape had been cut and iron bars were found near the tunnel.

At around 6.30am on Monday, the four fled from the roof of B Block and jumped the fence of behind the jail's clinic.

Last year, Davidson complained he was crammed into a small cell inside Kerobokan.
"There are 20 other people and yourself in the size of this little area here ... No bed, no nothing. You don't get anything," Davidson told AAP.

"In the corner you have a little bit blocked off that is a hole in the ground and that is your toilet and your shower."

He said if you didn't have 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."

But it was reported on Tuesday that Davison actually liked prison life in Indonesia.