A volunteer-run group is working to identify Queensland soldiers listed as missing in action during World War I through DNA testing.
The group is focusing on the remains of more than 200 Australian soldiers who were discovered in a mass grave in France almost two decades ago.
The grave is a remnant from the Battle of Fromelles, widely considered to be the worst 24 hours in Australian military history.
The first major action for Australian soldiers on the Western Front, in a single night on July 19, 1916 almost 2,000 Australian men were killed during an assault on German lines.
For almost a century hundreds of those soldiers remained missing.
In 2007 research by retired Melbourne teacher Lambis Englezos led to the discovery of a mass grave, containing the remains of 250 soldiers.
The Fromelles Association was formally established in 2014 with the aim of identifying them.
Volunteer Tony Ryan said when the mass grave was first opened many could be identified through unit badges, identification and letters from home that were still legible.
"But it's those 70 whose remains haven't been identified, that's where DNA comes in and the DNA connection is what we're really striving for now," he said.
The Fromelles Association has identified Queensland men who joined the 31st Battalion and remain unaccounted-for.
The group has spent years researching to try to establish links between the soldiers and their descendants who might be able to provide a DNA sample that would confirm their identity.
In some cases, volunteers have spent up to 4,000 hours establishing family links before getting in touch with someone they believe to be a family member.
Betty Petrie from Ayr, south of Townsville, could be a descendant of one of the soldiers.
Volunteers reached out last year to tell her they believed Private John Watson — a relative of her great-grandmother — was one of those missing soldiers.
"I was quite surprised, probably more surprised about the research they'd done to find me," she said.
"But I was only too happy to help get someone else identified."
Ms Petrie said she had "no idea" that one of her descendants had possibly served and lost his life in World War I.
"My grandmother never broached the subject at all on either side of my family. No one seemed to ever want to speak about war or who went," she said.
She's now waiting for a DNA kit to be sent from the UK.
Mr Ryan said DNA from both the maternal and paternal sides of the family are required for identification.
The lost soldiers from the battle of Fromelles represent just a small portion of unidentified Australians from World War I, Mr Ryan said.
"Thousands upon thousands were killed and had no known graves out of that whole Fromelles campaign," he said.
Mr Ryan also has a family connection to the battle through Private Ray Jordan, a 31-year-old NSW man who was killed in action at Fromelles and was never found.
"We did our family tree and one of those names matched one of the people who is possibly in this mass grave," he said.
"That was a very emotional thing when you think well, that could be my grandfather's missing brother."
