National Prosecuting Authority (NPA) acting director Mokotedi Mpshe told Talk Radio 702 he wanted to make progress on the matter urgently, but he added that no arrest was planned for Wednesday or Thursday.

Media reported earlier that Selebi, the national police commissioner who is widely believed to be the target of a probe into alleged ties to organised crime, would appear in a court in the capital Pretoria on Wednesday.

The embattled police chief, who is also president of international police organisation Interpol, has denied charges he is involved in criminal activity. He has admitted he is friends with Glenn Agliotti, a convicted drug smuggler.

The NPA said in October it had obtained arrest and search warrants for Selebi but would not act on them pending a review, sparking speculation Selebi was being protected by friends in the government.

South African President Thabo Mbeki has stood by Selebi despite calls by the opposition and media for him to be sacked, in part over his failure to reduce the country's high levels of violent crime.

Selebi, who was an African National Congress activist in exile during the struggle to overthrow white minority rule, is seen as an important ally to Mbeki, who is seeking a third term as leader of the ruling ANC at a December 16-20 party conference.

Mbeki must step down as the country's president in 2009. He is trailing presidential challenger Jacob Zuma for the ANC presidency after Zuma took a sizable lead in the race when results of the ANC branch nominations were announced last week.

Zuma was fired as deputy president by Mbeki two years ago after he was linked to a corruption case, but he remains extremely popular among leftists within the ruling alliance and those unhappy with what they see as Mbeki's autocratic style.

That popularity has helped Zuma to stay on as ANC deputy president, despite being tarnished by the ongoing corruption investigation and a separate 2006 rape trial. Zuma was acquitted of the rape charges.

The corruption case was thrown out of court earlier this year on a technicality, but prosecutors have suggested they may launch new charges against Zuma.