Vic murderer wants mercy petition: report

Victorian Attorney-General Martin Pakula will consider a petition for mercy if one comes from a convicted police killer who says he is innocent.

Jason Roberts is preparing to petition to Mr Pakula to reopen his case, the Herald Sun newspaper reports.

Victoria's corruption watchdog looked into the conduct of four police officers involved in the murder investigation.

Roberts and Bandali Debs were convicted of murdering police officers Sergeant Gary Silk and Senior Constable Rod Miller in 1998.

Mr Pakula said he hadn't seen a petition of mercy from Roberts, who reportedly still insists he is innocent.

"Some are well considered, some are what you might call highly speculative, but they're all given appropriate consideration and if one is received in regards to Mr Roberts it will be treated in exactly the same way," Mr Pakula told reporters on Tuesday.

A spokesman for the Independent Broad-based Anti-corruption Commission told AAP: "for legal and operational reasons we cannot comment" on the investigation.