The Japanese woman was walking in the Uluru Kata-Tjuta National Park when she collapsed on Sunday.

Police are now waiting for tissue samples to be analysed in Adelaide before they can say why the woman died.

Acting Superintendent Michael Murphy from Alice Springs police says the autopsy was inconclusive.

"At this stage the provisional cause of death is not yet determined," he said.

"What that means is the forensic pathologist has further tests conducted on tissue samples with histology and also toxicology reports.

"So that's about a turnaround of a month or so before he can determine the results of those tests."

Acting Superintendent Murphy says the woman's family have flown to Alice Springs from Japan to take her body home.

"Late last night the husband and three children flew into Alice Springs and they're in Alice Springs at the moment," he said.

"Obviously it's a fairly traumatic time for them and they'll be escorting the body home once our investigation and the coroner's investigation's concluded."

Police have not yet released the woman's name.