During the First World War the New Zealand Government had concerns that Rua opposed Tūhoe men enlisting for war, these concerns resulted in rumours that he openly supported Germany. The Government arrested Rua after a 1915 hahunga, a bone cleansing ceremony, where he allegedly supplied liquor without a licence. He was summoned to appear before a magistrate on 19 January 1916, Rua said he would appear at the February court session as he was busy harvesting cocksfoot grass but his non-appearance was deemed to be contempt of court and preparations began for an armed police expedition to arrest him.