Niamh Finneran Loader was found dead inside a Kuta hotel earlier this month.
The 25-year-old travelled to Bali for minor dental work that reportedly never took place.
Her body was taken to hospital by police on December 7 five days after she died.
An autopsy conducted found no obvious signs of trauma.
“We don’t know yet what happened during that five days,” forensic specialist Dr Nola Margaret Gunawan said.
”It’s still undetermined yet because we are still performing a thorough examination.”
Her death is under investigation by local police.
Officers are interviewing staff at her hotel and at the dental clinic where it is understood she was going to seek treatment.
The 25-year-old’s parents rushed to the island to bring her home and have hired lawyers to help get answers.
Loved ones have remembered her online as “a wonderful, kind, fun-loving young woman who brought brightness into everyone’s lives”.
“Not only a friend has died but also I think someone who really had a lot to offer,” friend Mark Burgess said.
A Department of Foreign Affairs and Trade spokesperson said the family is receiving consular assistance.
“Owing to our privacy obligations, we are unable to provide further comment,” the spokesperson said.
