More than 100 convicted Australian sex offenders tried to enter Indonesia between November 2014 and the end of last year, documents obtained by the ABC show.

Key points: Immigration and AFP alert Indonesia when a convicted Australian paedophile is travelling there

Immigration and AFP alert Indonesia when a convicted Australian paedophile is travelling there Offenders are turned away at airports

Offenders are turned away at airports NGO worker says Balinese community needs higher awareness of the dangers of paedophilia

They were turned away at airport borders as part of an arrangement between Indonesian and Australian authorities.

Under the agreement, Australian immigration officers and the Australian Federal Police alert Indonesia when a convicted paedophile is travelling to their jurisdiction.

The list, leaked to the ABC, shows the Australians' names, passport and flight numbers and date of travel to Indonesia.

Bali's police chief, Inspector General Sugeng Priyanto, has described paedophilia on the holiday island as an "iceberg" phenomenon: some offenders appear on the surface, but the real number is much larger.

"These paedophilia cases have to be stopped. That's why the police are taking two steps," he said.

"First is prevention, the other is repressive. Prevention is done through a campaign about the dangers for the under-aged, the repressive is done through law enforcement."

Australian man faces 15 years in jail over 16 offences

The ABC was granted access to the Bali police prison in Denpasar to film an Australian man facing serious child sex crime allegations.

Robert Andrew Fiddes Ellis, 69, is accused of shocking sexual abuse of at least 16 girls aged between seven and 17 over two years from 2014.

The ABC has confirmed he had no prior convictions in Australia and so Indonesian authorities were not alerted before his arrival in Bali.

Denpasar's prosecutor's office said the Australian had admitted guilt and faced up to 15 years in jail.

One of his alleged victims, known as Sekar, works at a local food market but barely makes enough to survive.

Sekar says she was paid by Ellis. ( ABC News: Samantha Hawley )

Ellis allegedly lured his victims off Bali's Kuta beach and gave them clothing, bikes and money.

He then allegedly took them to his home and bathed and sexually assaulted them.

"He gave me 100,000 rupiah, the biggest was 300,000 and I went there once and he gave me 250,000 (about $25)," Sekar told the ABC.

"At Kuta beach I was showering and he asked me to go with him. I went to his house in the afternoon and didn't go home until the morning."

Investigation expected to uncover more victims

Police Chief Priyanto said he believed there could be more victims.

"There are 16 alleged victims of Robert Ellis, but the real number is more than that," he said.

"The investigation process is still going on. We will try to look for the link, whether this is part of an international syndicate or he's just solo."

Lu Anggraeni, from Lentera Anak Bali, an NGO that helped uncover the alleged abuse, said she believed Ellis's history in Bali dated back to 2010, although the allegations against him arose over two years from 2014.

Lu Anggraeni says the Balinese community is not aware of the dangers. ( ABC News: Samantha Hawley )

"The victims told us they showered with him and he bathed them. They were naked and he touched them," she said.

"There was one that said 'it hurts', but he said 'it's OK, I'll buy you presents'."

Lu Anggraeni said the Balinese community did not have a high enough awareness of the dangers of paedophilia.

"They don't know that the paedophiles' approach is grooming these kids," she said.

"I have told people in the tourism sector, if the hotel receptionist sees a foreigner with a street kid, please be aware."