Police Minister Bheki Cele has appealed to the public to give police the "space" to thoroughly investigate the murder of Independent Police Investigative Directorate (IPID) investigator Mandla Mahlangu.

"At this early stage of the investigation by the Gauteng Provincial Investigating Unit, it is important to allow police the space to investigate thoroughly the circumstances surrounding the shooting incident," said Cele.

The minister expressed his condolences to Mahlangu's family as well as those who worked closely with him.

Mahlangu, 47, was shot and killed in the early hours of Tuesday morning on a smallholding at De Ruxia, outside Cullinan, east of Pretoria.

Independent Police Investigative Directorate (IPID) Spokesperson Moses Dlamini has denied allegations that Khomotso Phahlane's arrest was a show for the media.

It is alleged that five gunmen stormed into his residence and shot him.

Police spokesperson Brigadier Vishnu Naidoo said the gunmen arrived at the property at about 03:30 and held Mahlangu and a worker at gunpoint.

"The suspects shot Mr Mahlangu and fled, taking with them [his] white Nissan Hardbody NP300 bakkie, registration JD23XFGP, and some household items," he added. 

Investigation

Mahlangu investigated corruption allegations against former acting national police commissioner General Khomotso Phahlane.

This was linked to the alleged purchase of a sound system, valued at R80 000, for the former police chief by the co-directors of a private company. Phahlane said he produced proof of payment.

Mahlangu also investigated how he managed to afford a house, said to have been valued at up to R8 million, which Phahlane maintained was built for R3 million.