That marks the start of the retrial of the group of activists and former politicians who were involved in an anti-government protest in 2015.
They face charges including rioting and disrupting the legislature.
RNZ Pacific reports they were awarded a permanent stay on proceedings last year by Supreme Court Judge Geoffrey Muecke, which was later dismissed by the Nauru Court of Appeal.
This month, newly-appointed Supreme Court Justice Daniel Fatiaki rejected another stay application and refused the Nauru 19 an appeal of this.
