A challenge by prosecutor Glynnis Breytenbach against her suspension from the National Prosecuting Authority has failed.

Johannesburg Labour Court Judge Hamilton Cele dismissed her application, and said no costs were ordered.

"The applicant has not shown the existence of any extraordinary or compelling, urgent circumstances to justify a final declaration of the unlawfulness of her suspension," Cele said in his judgment.

"There are reasonable prospects that if the disciplinary hearing against her is persisted with, it will be finalised within a reasonable time period. If not, she may refer an unfair labour practice."

Cele said the court would only intervene in uncompleted disciplinary proceedings in "exceptional circumstances".

He said however that if the NPA did exercise its right to discipline Breytenbach, it could be found to be "flouting and frustrating" the aims of an investigation ordered by the High Court in Pretoria into the suspension of former intelligence boss Richard Mdluli.

"It has been shown in these proceedings that the applicant will probably be a vital official in that probe," said the judge.

"If she is found guilty and dismissed, she will be handicapped from utilising the tools of the trade that she might need in these investigations. The justice sought to be striven for in the matter of General Mdluli would have been seriously compromised."

Breytenbach was suspended as regional head of the specialised commercial crime unit on April 30, allegedly for conduct relating to cases allocated to her.

Breytenbach contended that she believed acting national director of public prosecutions Nomgcobo Jiba suspended her in an attempt to protect Mdluli.