With help from the RSA and the French Embassy, the documentary crew flew to New Zealand after learning of the family's story through the New Zealand Commission in France, which was dealing with the family's upcoming wedding next month.
Awanui Black, part of the wider Webster family, said the documentary makers jumped on the story because they were working on a project about fallen foreign soldiers buried in France.
"And in France there's very little known about the contribution of New Zealand and nothing about Maori.
"They found the story really intriguing."
Mr Black said the documentary focused on a Canadian man, a man from the United States and his ancestor Jack Webster.
Mr Black said the contribution of Maori from the Western Bay in World War I was significant.
"It was an opportunity to see the world.
"They were also encouraged in many respects to go to show their solidarity with New Zealand and with the British Empire in the hope that Maori would be considered equal in this country. It was actually referred to as the 'price of citizenship'.
"So there are all these emotions happening on Friday," Mr Black said.
"We also had the last of our elders, in their 80s and 90s, who remember those people, so it was very tangible for them."
The documentary crew arrived last week and flew out yesterday.
Gus Webster, who is the eldest living male descendant in the Webster family, said his cousin was getting married next month in the Czech Republic and an entourage of whanau were heading over for the event.
As part of the trip, the family would make the journey to Calais in France where their great-grand-uncle was buried.
Jack Webster never had any children, but descendants from his parents would span to about 250 people in the Western Bay.
