South African opposition parties are demanding clarification over reports that prosecutors issued an arrest warrant for the commissioner of police.
Police chief Jackie Selebi is the current head of Interpol
The National Prosecuting Authority (NPA) has not commented on the reports in which media quoted unnamed sources.
Commissioner Jackie Selebi is also the current head of the international police body, Interpol.
Opposition parties say if reports of the warrant are true, he should be suspended from his post.
Previous press reports have linked Mr Selebi to Glenn Agliotti, who was arrested last year in connection with the murder of leading businessman Brett Kebble. Mr Selebi has denied having business links with Mr Agliotti.
On Friday, reports suggested that President Thabo Mbeki's decision last week to suspend Chief Prosecutor Vusi Pikoli was linked to the investigation into Mr Selebi.
Helen Zille, leader of the opposition Democratic Alliance, said the latest reports needed to be either confirmed or denied as a matter of urgency, and called on President Mbeki to provide clarification.
"We are entering a phase in our democracy where the most serious questions, with profound constitutional implications, are being asked about the conduct of the president and the national police commissioner," Ms Zille said.
Pikoli was suspended last week, reportedly while investigating Selebi
"The president needs to take the nation into his confidence."
Inkatha Freedom Party (IFP) spokesman Velaphi Ndlovu issued a statement putting a question to Mr Mbeki: "Has a warrant of arrest, or any warrant, at any stage, been applied for against Mr Selebi?"
The African Christian Democratic Party called for Mr Selebi's suspension from his duties, while the Freedom Front Plus called for a judicial inquiry into the allegations around the commissioner of police.
The warrant for Mr Selebi's arrest was reportedly issued by the NPA, which operates independently from the South African Police Services, the regular police force headed by Mr Selebi.
Reports say the NPA issued the warrant last week, before Mr Pikoli was suspended from his duties by President Mbeki.
The role of the NPA's Special Investigations Unit, known as the Scorpions, and its relationship with the police has been the subject of intense political controversy in South Africa over the past four years.
Mr Pikoli's suspension followed reports of disagreement with Justice Minister Brigitte Mabandla over the role of the NPA and the Scorpions in the prosecution of former Deputy President Jacob Zuma on charges of corruption.
But Friday's Mail & Guardian newspaper suggested that Mr Pikoli's suspension resulted from his failure to inform his political superiors of moves to investigate Mr Selebi.
Political commentator Adam Habib said Mr Mbeki would have to deal decisively with the latest claims.
"If there's a link [between Mr Pikoli's suspension and investigations into Mr Selebi] this will have serious implications, because the constitution says the NPA must be free and independent of political interference," he said.