Investigators said they carried out an exhaustive search to trace living links to Private James Rowan, whose family are believed to be from Co Longford, but the results were inconclusive.
It is understood a number of people from Longford, as well as a Manchester-based priest called Fr Rowan, came forward after an appeal last year following the discovery of the soldier’s suspected remains.
Longford’s county archivist was also enlisted into the search, but Lynne Gammond, of British army headquarters at Andover, Wiltshire, said they could not prove any family connections, despite trawling through family trees and other historical documents.
“There was a huge response but we just couldn’t make the link,” she said. “We have DNA from the remains, so if anyone can prove a positive link in future, then we can still carry out tests.”
Pte Rowan’s suspected remains were among six sets found close to a railway siding outside the Belgian village of Comines-Warneton just five years ago. Aged 30, he was killed on a battlefield at the site on October 20, 1914. The remains were found by an amateur archaeologist during a dig.
Having cross-referenced military records, including war and regimental diaries kept from the time, the UK Ministry of Defence (MoD) Joint Casualty and Compassionate Centre believe the remains are those of Pte Rowan.
However, they need to establish a firm family link, and confirm through DNA testing, to conclusively prove the identity.
The soldier’s family is believed to have moved from Co Longford to Lancashire, where he was born in the late 1800s.
As a young man he took a job as a miner at Park Lane Colliery near Wigan, before going on to enlist with the 1st Battalion The Lancashire Fusiliers.
He is among those remembered on the Ploegsteert Memorial in Flanders, which records the many missing in the First World War.
It is believed the Rowan family moved back to Co Longford.
The MoD said it carried out “exhaustive research” and is now planning a re-interment and memorial service for Rowan and his five comrades, also designated unknown. The ceremony, with full military honours, will take place on April 16 at the Prowse Point Commonwealth War Graves Cemetery in Belgium.