Prime Minister John Key's show on RadioLive in the run-up to last year's election has been found to have breached the law and has been referred to the police.
NewstalkZB says it has a copy of the commission's decision, which it says found that the show, hosted by Mr Key in September, was an election programme and a breach of the Broadcasting Act.
The commission confirmed on Thursday it had referred the matter to police.
The Labour Party complained to the commission over the hour-long broadcast and the report says a breach of the act took place.
The ruling is due to be officially released at 5pm on Thursday.
The Broadcasting Standards Authority earlier found that the programme was not an election programme.
Police will now decide whether to prosecute and RadioLive could be fined up to $100,000.
The show on September 30, which featured interviews with the likes of All Blacks captain Richie McCaw and entrepreneur Sir Richard Branson, was aired during a three-month pre-election period where there are strict controls on advertising.