Bloemfontein - Martin Keevy, one of the Mangaung Rightwingers, will not be prosecuted alongside his two co-accused in the Free State High Court on Monday.
Judge Albert Kruger today declared Keevy unfit to stand trial and ordered that he be held at the Free State Psychiatric Complex.
According to his legal team, Marius Bruwer and Stefan de Beer from Hugo & Bruwer Attorneys in Bloemfontein, Keevy was examined by four psychiatrists, who unanimously found that he is unfit to stand trial.
The fourth accused, Hein Boonzaaier, was last month acquitted of all charges against him in the Bloemfontein Magistrate's Court.
The remaining two, Johan Prinsloo and Mark Trollip, will be tried from Monday onwards during which 36 witnesses will testify for the state.
They are facing charges of high treason and conspiring to commit acts of terrorism. They allegedly planned a coup by killing top ANC leaders during the party's Mangaung conference last year.