The timeframe is unclear for an independent inquiry into the confessions of a former undercover policeman who says he lied under oath.
The police hired a Wellington lawyer earlier this year to investigate the claims made by Patrick O'Brien in an open letter sent to Chief Justice Dame Sian Elias in 2007, and on a television current affairs show.
Mr O'Brien, who worked on covert drug operations while an undercover agent in the 1970s, says he lied to juries to get more than 150 convictions.
He has also claimed to have tampered with evidence in an effort to secure convictions.
Mr O'Brien says he is willing to plead guilty if charged with perjury.
In a statement, Assistant Police Commissioner Gavin Jones said police are waiting for a report from Bruce Squire, QC.
When spoken to on Sunday, Mr Squire said his investigation into the claims is still progressing.