The SA Policing Union (Sapu) on Friday called for the immediate disbandment of the specialist National Intervention Unit (NIU) after claims its members killed fellow policemen.

The union said there had been consistent allegations of this unit being a law unto itself, taking part in acts of barbarity and ill-treatment of suspects.

The union also called for the dismissal of national police commissioner Gen Khehla Sitole claiming he was "rewarding the NIU members for their loyalty to him".

The union said it had taken note of the latest allegations that two junior officers who were accused of robbing a post office in KwaZulu-Natal in the recent past were killed during a shootout with members of the NIU earlier this month.

The NIU was officially established in 2000 to address medium-risk and high-risk policing duties, specifically at incidents of violence where normal policing was deemed inadequate. The NIU's units are based in Durban, Pretoria, Cape Town and Mthatha.

Sapu general-secretary Tumelo Mogodiseng said the union initially called for the Independent Police Investigative Directorate (Ipid) to probe that incident as was normal procedure.

"We are now calling for the Human Rights Commission to take centre stage in this investigation. Allegations of those members being executed cannot be ignored any longer."

Mogodiseng said it was "a well-known fact" that Ipid lacked capacity and independence from the police.

Mogodiseng said Sapu had written a letter to President Cyril Ramaphosa calling for his swift action in relieving the national police commissioner from his position.

"It is clear Gen Sitole is rewarding the NIU members for their loyalty to him. We cannot allow patronage in the police. The brutal killing of those members is totally unacceptable."