The Irish Government feared that pistols taken from Roger Casement after he landed at Banna Strand in 1916 were improperly sold in 1990 and possibly illegally exported.
According to files released this week by the National Archives, a US gun collector had asked for copies of awards given to Casement.
In 1990 the collector had purchased the German Luger nine millimeter firearms which were believed to have been kept at Clancy Barracks in Dublin over the years.
Richard Stokes, then assistant secretary at the Department of the Taoiseach, wrote in March 1990 that 'it would seem they were improperly obtained and have perhaps been illegally exported.'