The National Prosecuting Authority has no evidence to support its corruption case against suspended police chief Jackie Selebi, he said in an interview published on Thursday.

"These people do not have a case... This is an unfortunate investigation, they do not know what they want," Selebi told the Sowetan newspaper.

He was reacting to the NPA's decision to serve subpoenas on witnesses --reportedly at least 10 senior police officials, including acting police chief Tim Williams -- to hand over evidence needed to prosecute Selebi.

The suspended national police commissioner said when the Scorpions first laid charges of corruption and defeating the ends of justice against him, "they told the public... they were ready to prosecute".

But Selebi said the issuing of subpoenas indicated that the NPA had no case against him and that it was conducting an "on-going fishing exercise".

Selebi is expected go on trial in the Johannesburg High Court on April 14 to face the charges relating to payments of about R1.2 million made to him.

"What they are not going to get, is another postponement," Selebi told the Sowetan.

The state alleges that convicted drug trafficker Glenn Agliotti, murdered mining entrepreneur Brett Kebble and former Hyundai boss and mining entrepreneur Billy Rautenbach and other "relevant corporate entities" made corrupt payments to Selebi between January 1, 2000 to December 31, 2005.

Selebi was suspended in January 2008 when he also quit as head of Interpol.