Section 8(1)(a)

if after the commencemnt of a trial by Commissioners under this Act any person surrenders or is arrested who, in the opinion of the [appropriate Government might, if he had surrendered or been arrested before the commencement of the tial, have been tried jointly with the person under trial the [appropriate Goverom nt] may direct that he shall be placed on his trial jointly with such other persons at the said trial: