Former national police commissioner Jackie Selebi has asked his lawyers to tell "authorities" that his corruption prosecution may have been improper, according to a statement attributed to him on Friday.

"Information has recently been discovered suggesting that the investigation and prosecution which led to my conviction have been improper," he said a statement forwarded by his lawyer Wynanda Coetzee.

"You will appreciate that it has been consistently argued during the trial that the actions taken against me were improper, manipulated and based on ulterior motives.

"Today, I have instructed my legal representatives to notify the authorities of this information and to direct their attention to this."

According to the statement, which was issued ahead of his application for leave to appeal his 15-year sentence on Monday, he would not elaborate or entertain any questions or public interactions.

"I do not wish to elaborate further on the content thereof, suffice to state that I have full trust in the relevant authorities to investigate these allegations and determine their veracity."

Selebi has already said that the prosecution against him was related to a dispute over the dissolution of the Scorpions, a special unit within the National Prosecuting Authority which began the investigation against him.

The Scorpions were dissolved following a resolution by the ruling African National Congress (ANC).

The Hawks were formed in their place, but were situated within the police instead of the NPA. In July, Judge Meyer Joffe handed down the sentence against Selebi.

It was the maximum for a crime of corruption involving a law enforcement official and an amount over R10 000.

"The NPA has noted the statement attributed to Mr Selebi, however we won't be commenting on it as prosecutors are focusing on the leave to appeal which is scheduled to be argued on Monday," said NPA spokesperson advocate Mthunzi Mhaga.

He was not aware of the receipt of such information by the NPA.