Police Minister Nkosinathi Nhleko's decision to suspend Hawks boss Anwa Dramat was invalid, the High Court in Pretoria ruled on Friday.

"The order which I make is the following: it is declared that the decision of the minister of police to suspend Lt-Gen Anwa Dramat, the national head of the DPCI [Directorate for Priority Crime Investigation] is unlawful and invalid," Judge Bill Prinsloo said.

"It is declared that the decision of the minister, appointing Maj-Gen Berning Ntlemeza as acting national head of the DPCI is unlawful and invalid. That decision is set aside."

The Helen Suzman Foundation (HSF) approached the court, asking it to set aside Nhleko's decision to suspend Dramat and the subsequent appointment of Ntlemeza.

Dramat was suspended on December 23, pending a probe into his alleged involvement in the illegal rendition of four Zimbabweans in November 2010.

The HSF maintained the wording of the South African Police Service Act, under which Nhleko purportedly made the decision, had been struck down by the Constitutional Court, making Dramat's suspension invalid.

David Unterhalter SC, for HSF, argued previously that the "decapitation" of the head of such a critically important crime and corruption fighting unit was gravely damaging to his office and public confidence in the independence of the unit.

"It is simply a case of unlawful conduct by the minister and we ask that the court intervenes," he submitted.

He said the timing of Nhleko's actions was suspicious.

"It is rather extraordinary that he is said to be deeply worried, but he waited for months after being appointed [police minister]. That is inexplicable," said Unterhalter.

He said the law stipulated that the head of the crime combating unit could be suspended only following a parliamentary process.

On Friday, Prinsloo concurred with Unterhalter.

"It is declared that the minister is not empowered to suspend the national head of the DPCI other than in accordance with Section 17d A3 of the South African Police Service Act of 1995," said Prinsloo.

He ordered Nhleko to pay the HSF's legal costs.