Bali police have arrested a man they believe was responsible for raping a young Australian woman at knife-point during a robbery at her rented Kerobokan villa in late April.

Details remain scarce, but North Kuta police chief Reinhard Nainggolan said they had arrested the man early on Monday morning.

"We are coordinating with the Australian Federal Police representative in Bali, to positively identify the suspect," Mr Reinhard said.

"We arrested him in Bali. The suspect claimed the items stolen from the villa were sold off, but we are still confirming that. It wasn't the only robbery he committed, it's an ongoing investigation."

The rape took place at 4am on April 27 in the bedroom of the VillaDarmais, where the 28-year-old Perth woman was staying with eight members of her family.

The thieves jumped the wall surrounding the villa while a guard was away from his post and then let themselves in an unlocked door.

Inside the house, one of the three men singled out the woman and sexually assaulted her at knife-point, police say, while the others proceeded with stealing mobile phones, iPads and cash from the rooms.

Others family members, including children, slept through the attack in other rooms.

The victim filed a police report, underwent a medical check and provided them with a sketch of the perpetrator before returning to Australia.

Mr Reinhard said the alleged rapist was the only one of the three men involved in the robbery who has yet been arrested.

He said the suspect was "currently being taken to identified other crime scenes and to assist with the arrest of his partners".

The victim has been advised of the arrest.

A spate of crimes has hit Bali in recent months, often blamed on poor Javanese construction workers brought to fuel the island's construction boom.

Long time residents say the crimes, including robberies and sometimes violent home invasions, have disproportionately hit tourists and expatriates staying in villas.

with Amilia Rosa