The National Prosecuting Authority (NPA) is conducting an internal probe into the prosecution of convicted former national police commissioner Jackie Selebi, The New Age reported on Thursday.

According to the report, a misconduct complaint was laid by Selebi's family and legal team that the prosecution did not reveal all the evidence in its possession during the former police commissioner's trial.

Suspended integrity management unit head Prince Mokotedi, who was expected to resign from the NPA on Friday, confirmed to the newspaper that the complaint was being investigated.

"I know that senior prosecutor Shawn Abrahams has been appointed to look into the matter," he said.

"He has collected the Selebi docket from the Hawks and is studying the contents."

Selebi's lawyer Wynanda Coetzee said on Wednesday they had approached the NPA regarding the way the case was handled.

Selebi was sentenced to 15 years' imprisonment on August 3, 2010 for taking bribes from convicted drug dealer Glenn Agliotti.

He collapsed at his house in December 2011 after his final appeal failed.

Selebi was released on medical parole in 2012 after he was diagnosed with kidney failure, hypertension and diabetes.