Schapelle Leigh Corby, 27, of Tugun on the Gold Coast, was being held at the same prison as the convicted Bali bombers after being arrested at Bali airport two months ago for allegedly bringing 4.1 kilograms of high-grade marijuana into the island.

Police were required to revise their brief of evidence against her after prosecutors returned the initial report, saying it was incomplete.

The dossier was yesterday handed to the prosecution for the second time, anti- drugs squad detective Gusti Ngurah Gunardi told journalists at Bali police headquarters.

"We are now waiting for their assessment. If they conclude that the investigation is complete, then we will also hand over custody of the suspect and evidence," he said.

He said police had added extra information on how customs officers had detected the marijuana in Corby's bodyboard bag and how they apprehended her, as well as information on baggage security at Bali airport.

Corby alleges the drugs were planted in her luggage, claiming she had never before laid eyes on them.

Meanwhile, Vasudeva Rasiah, a member of Corby's legal team, said his client had yet to decide whether to allow Australian Federal Police experts to conduct tests on the origin of the marijuana.

If tests proved the marijuana was from Australia, it could be detrimental to her case.

The 27-year-old from Tugun was arrested in Denpasar last month when customs officers allegedly found more than four kilograms of cannabis in her luggage.

Her mother Ros Leigh says investigations have progressed slowly since the arrest.

But she says Indonesian authorities interviewed her daughter again yesterday, and there are finally some positive signs.

"I think they were just leaving it and thought they've got a guilty party and they've picked on the wrong girl," she said.

"She's never been in trouble with the law before - the federal police have told them that here - and all her drug tests have come back negative."