Bloemfontein - One of the accused in an alleged plot to attack the ANC's 2012 Mangaung Conference, Johan Prinsloo, appeared in the Free State High Court on Tuesday.
Judge Johann Daffue postponed the matter to 12 May.
Prinsloo, 51, from Springs, Gauteng, faces charges of treason and conspiracy to take part in terrorist acts, as well as possession of illegal ammunition.
Prinsloo, Mark Trollip, 48, and Martin Keevy, 49, were arrested in connection with the alleged plan to attack delegates at the African National Congress's conference on 16 December 2012.
Trollip has already pleaded guilty to a charge of conspiracy and was sentenced to eight years in prison last year. In October, Keevy was declared unfit to stand trial and declared a patient of the State.