A statement by a police spy and state witness in the Boeremag treason trial concerning an unrelated murder investigation yesterday resulted in heated argument and an application to gag the media.

Prosecution leader Paul Fick asked judge Eben Jordaan to rule that the press could not publish a statement by Johan Smit, the police spy who infiltrated the Boeremag's alleged inner circle and is one of the state's chief witnesses against the 22 accused.

The statement in dispute relates to the murder of Smit's former boss, Nic van Rensburg, who owned the First Defence Training Institute in Centurion. Rightwinger Chris Streicher has been arrested in connection with the murder and will, according to the state, go on trial in Pretoria High Court later this year.

Attorney Daan Mostert, who represents the accused Adriaan van Wyk, wanted to use the statement in Smit's cross-examination, claiming it was relevant and related to Smit's credibility but the prosecution strenuously objected, saying that it was not relevant at all.

Smit has been fending off a series of pointed questions by the defence since the trial resumed last month.

He has been accused of "selling" information to the police and "manipulating" his police handler - which he denied.

Jordaan did not make a ruling about the statement yesterday, instead postponing the trial until Monday and asking Mostert to prepare written argument on the issue. – Sapa.