The DA says it wants to know who approved the release of convicted former national police commissioner Jackie Selebi on medical parole.

Democratic Alliance MP James Selfe said in a statement  that neither Correctional Services Minister Sibusiso Ndebele, nor National Commissioner Tom Moyane or the Medical Parole Advisory Board, had "answered the public's criticism" on Selebi's release.

Selebi, who was convicted of corruption in 2010, was released from Pretoria Central Prison on medical parole last week, after serving 229 days of a 15-year sentence.

"The real question around the release of Mr Selebi is, who made the decision to grant him medical parole?

"In terms of... the Correctional Services Act, an application for placement on medical parole must be considered by the minister, the national commissioner or the parole board. It is not clear who exactly made the decision to release Mr Selebi," said Selfe.

If the application was considered and approved by the minister or the national commissioner, the question arose as to whether political concerns trumped the medical factor.

Selfe said he would submit questions to Ndebele to determine "who approved the release of Mr Selebi on medical parole; which factors did they take into consideration when determining [this]; and, were complainants allowed to make representations about his proposed placement on parole".

Ndebele last week announced that Selebi was one of 12 terminally ill prisoners whose applications had been reviewed by the Medical Parole Advisory Board.

He said at the time that the 12 had illnesses which had reached an "irreversible stage".