Almost 20,000 Irish soldiers fought in the Canadian army during World War I new figures show.

According to an unpublished document from Canada’s Department of National Defense, 19,327 Irish served in the Canadian Expeditionary Force.

However, the Irish Times reports that number may be underestimated as many Irish who enlisted in the army came from across US border and would have been regarded as American.

Canada went out of its way to recruit Irish soldiers and a number of Irish battalions were raised during the war.

The Canadian Expeditionary Force and and an Irish regiment, the Royal Irish Lancers, were involved in the liberation of Mons on Armistice Day 1918.

Figures suggest that about 2,000 Irishmen probably died in the war while fighting for Canada.

Jimmy Duffy was one of 11 men form Co Sligo who died in the Canadian army. Regarded as one of the best marathon runners in the world at the time, he won the 1914 Boston Marathon. He was living in Canada at the time  and enlisted in the Canadian army. Duffy was killed at the Second Battle of Ypres in May 1915. It was just eight days before his 25th birthday.

He and the other Sligo men wo died are included in a new local history project aimed at finding a more definitive number of the war dead from Ireland.

The Australian government lists 4,731 Irish-born soldiers who served in the Australian Expeditionary Force during the war, while the New Zealand Expeditionary Force lists 1,300. The British army saw 206,000 Irishmen join its ranks with at least 31,000 killed.

The Irish-born population in the United States was around 1.3 million in 1910, and it is estimated that some 40,000 Irishmen served with the American army.

A definitive number has never been established as to exactly how many Irish soldiers died fighting in the war.

Trinity College Dublin (TCD) historian Professor John Horne, an  expert on first World War casualties, told the Irish Times that it is “unknown” how many Irish  fought and died in all armies in the war.

According to Irish War Memorial Records, there are 49,400 dead from Irish regiments in the war, but not all of those killed were Irish and many of the Irish, who died in non-Irish regiments, are not included.

Horne says more research needs to be done, but the task of ascertaining for certain the number of military dead in the war is “hugely complex.”