President Cyril Ramaphosa placed police minister Senzo Mchunu on immediate leave of absence on Sunday, following accusations by a top police official that he had colluded with a criminal syndicate and interfered in high-profile investigations.

Mchunu denied the allegations by Nhlanhla Mkhwanazi, police commissioner of KwaZulu-Natal province, at a media briefing last Sunday. He said the accusations were baseless and in a statement issued by his spokesperson last week said he was committed to upholding the rule of law.

Ramaphosa, whose rise to the highest office was built on promises to fight corruption, has been under pressure to act swiftly as political parties and citizens said the allegations called into question the integrity of the criminal justice system.

Investors have for years expressed concern over rampant crime that the World Bank estimates costs South Africa an estimated 10% of gross domestic product each year.

"These allegations therefore call for an urgent and comprehensive investigation," Ramaphosa said in a public address which was carried by the public broadcaster and private TV stations, adding he would establish a judicial commission of inquiry for this purpose.

Ramaphosa said he will appoint law professor Firoz Cachalia as acting minister of police.

Mchunu is a senior figure in Ramaphosa's African National Congress (ANC) party, and political analysts have said he could run for a leadership position at the ANC's next elective conference in 2027.

Citing digital evidence such as WhatsApp messages, Mkhwanazi's allegations included that Mchunu had disbanded a police unit tasked with investigating politically motivated killings to protect politicians, police officers and other people linked to a criminal syndicate.

Mkhwanazi said more than 100 case files were taken away from the political killings task team and have not been investigated further since.

The Democratic Alliance party, the ANC's main coalition partner, called for a parliamentary inquiry into the allegations against Mchunu. At least one opposition party has called for his suspension.