It sounds like the plot of a thriller movie.
A young woman disappears from a remote beach in outback Australia, only for her family to discover decades later that she's moved overseas and is married with children.
But it's not a movie. It's exactly what happened to Don Wininba Ganambarr and his family.
WARNING: Aboriginal and Torres Strait Islander readers are advised that this article contains images of people who have died.
Now, Don's genetic links and the oral history he has been told are helping to map the little-known migration of Indigenous Australians to South-East Asia prior to British settlement.
"I think it tells an incredibly interesting story of Australia's history," says Professor Lynette Russell, who is researching the era.
"There's a perception that Aboriginal people were isolated, and yet here they are — international travellers."
Mystery photographs
The existence of a community of Aboriginal people living in Indonesia in the 1700s and 1800s was brought to light by the discovery of photographs showing young men posed in a studio in Makassar in 1873.
It's believed the group was among a significant number of Indigenous people who travelled from northern Australia to Indonesia with visiting trepang fishermen.
The ABC is now working with researchers and elders to build a picture of the little-known overseas settlement.
Among those who know the history first-hand is Yolngu elder Don Wininba Ganambarr.
Don grew up hearing stories about the disappearance of his grandmother.
"The old people said she was taken away," he recalls.
"All they saw was her footprints on the sand, and from there she went missing.
"I think there were a lot of people who were taken from Arnhem Land to Indonesia."
Decades later came surprising news.
It was confirmed that the young woman — Don's grandmother — had left with visiting trepang fishermen, and moved to Makassar where she married and had children.
By the time Don found out, his grandmother had passed away, but in 1978 he travelled to Indonesia to meet his relatives.
"It was very emotional, because they had missing family, and we had missing family," he says.
"Some of them looked like my grandmother, and I knew for sure when I saw paintings in their house of her [Yolngu] totem.
"She is buried in Sulawesi, but I haven't seen her grave, so I'm hoping to go back again soon."
It is not known whether Don's grandmother left voluntarily or was forced to leave by the fishermen.
Some Aboriginal elders, from other coastal areas, have told the ABC women were likely traded, as part of an ongoing exchange of goods and knowledge.
Don says he knows of several other Yolngu people who moved to Makassar.
"Maybe it was friendly, like an invitation of friendship … 'You are my best friend now, you can come back with us'," he suggests.
Global research
Don has shared his family's story with a research team currently mapping early visits to the Australian continent by people from Europe and Asia.
The project — called Global Encounters and First Nations Peoples — focuses on interactions with Indigenous people prior to British settlement.
Professor Russell, who is leading the research, is due to travel to Makassar this year to document the family links.
"I think there's every chance that there are descendants Indigenous people who stayed in Makassar," Professor Russell says.
"In particular, from Makassan men who took Aboriginal wives who may have travelled back with them.
"There is certainly the potential to use DNA to flesh out the story a bit more."
The research team is using a variety of methods to document the early visits by sailors from countries including France, Portugal and Indonesia.
Linguists are studying how and when foreign words first appeared in local Aboriginal dialects.
Dating techniques are being applied to tamarind trees growing along Australia's northern coast, to work out when they were first introduced by Indonesian fishermen.
Professor Russell says an interactive digital map is being created to show the different voyages and contacts that reached northern Australia from around the world.
The map will soon be made public.
"There's a perception that prior to the arrival of the British, Australia was an isolated location that hardly anybody ever visited," she says.
"Of course that's simply not true."
'We are blood'
Don is hoping to reconnect with his Indonesian relatives again soon.
A few years ago, some members of his Indonesian family visited the Northern Territory.
"When they had to catch the flights to go home they were crying," he reflects.
"They were crying because we're blood, and they've got Yolngu blood in them.
"When someone is taken away, it's like a storm of clouds — part of the cloud breaks away and never comes back."
The Yolngu elder says he is open to DNA testing if it helps confirm the family connection.
Will photo mystery be solved?
The question remains as to the identity of the young men and boys in the 1873 studio photographs.
But a tantalising clue has emerged from a remote community on Australia's northern coast.
A Yolngu family who saw the February coverage has come forward with a possible identification, based on appearance, oral history and scarification.
The ABC is now working with the community and anthropologists to investigate the potential connection.
