TVNZ has now joined MediaWorks in a police inquiry over election coverage.
MediaWorks is being investigated over an hour-long show in which Prime Minister John Key interviewed All Blacks captain Richie McCaw, British billionaire Sir Richard Branson and filmmaker Sir Peter Jackson.
The show aired prior to the election and the Electoral Commission today said it had referred MediaWorks to the police for breaching the Electoral Act.
The commission has announced that it has also made a police complaint over One News coverage on the night of the November election.
The commission said TVNZ's coverage before 7pm could have influenced voters.
"It is the Electoral Commission's view that the broadcast breached section 197(1)(g)(i) of the Electoral Act 1993 because it included statements that were likely to influence any elector as to the party for whom the elector should or should not vote," it said.
The announcement came as the commission released details of its decision to refer MediaWorks to the police over its "Prime Minister's Hour" chat show.
While the show was not an election advertisement it was "an election programme".
It was unusual for broadcasters to provide a person contesting an election as a party leader and candidate with the opportunity to host a radio programme in the lead up to the election, the commission added.
The test was whether the programme would be perceived as encouraging or persuading people to vote towards a certain party or candidate, or appearing to do so.
The commission said it was reasonable to conclude it would.
RadioLive had asked for an advisory opinion from the commission two days before the broadcast.
The advice was "necessarily general" because the show was unscripted and live and only a brief outline of its contents was available.
The commission's advice was that broadcasters needed to exercise "a high degree of caution" with such shows.
Today it issued advice to broadcasters that in future programmes that were hosted by a leader or candidate and broadcast close to an election it was likely to be an election programme and therefore in breach of the act.
KEY SHOULD BE INVESTIGATED, PETERS SAYS
New Zealand First leader Winston Peters says John Key should also be referred to police over his hosting of a radio show, not just RadioLive.
The Labour Party complained to the Broadcasting Standards Authority (BSA) and the commission stating the show breached the Broadcasting Act and that it was unfair their leader at the time, Phil Goff, was not allocated equal time.
The BSA cleared the Prime Minister of any wrong-doing but the commission, while finding the show was not an election advertisement, found it did constitute an election programme. As such it has referred the matter to police.
Police this morning announced they had received the complaint and said it would now be assessed.
Peter said this afternoon the show was designed to get around the rules.
"It was a stunt, just like the tea party was and he's been caught out," he said.
He also said it took "far too long" for the commission to decide to refer the complaint and should have been resolved before the election.
"Something like that begs the question as to what these authorities are doing."
But National's campaign manager Steven Joyce said that was not the law.
"My understanding when I was a broadcaster is that you are responsible for what you broadcast and that was always pretty clear from where I was sitting."
In response to Parliamentary Questions this afternoon, Gerry Brownlee said Key's office had discussed the programme with RadioLive who sought advice from the commission and chose to go forward with it.
Labour said today it felt vindicated over the Electoral Commission upholding its complaint.
NewstalkZB said it had obtained a copy of the report, which found the show violated the act. RadioLive could be fined up to $100,000 for the breach.
Labour felt the real damage had already been done, though, as Key had been able to go through the election campaign with the benefits of an "unfair election programme".
Labour deputy leader Grant Robertson said the show gave Key an advantage in the election campaign.
Asked whether Labour would have won the election had it not gone ahead, Robertson said that was not what the complaint was about.
"What this gave the Prime Minister was an unfettered hour of radio in which he could put across himself, align himself with the people he called his friends and be in a situation close to the election where he had that hour when he was in an unfettered environment, that gave him a lot of power at that time."
"At the time that the BSA decision came out we disagreed with it, we felt that this was a clear breach of election broadcasting law and that it was unfair."
Robertson said he had not listened to the programme cause he was too busy campaigning.
"One good thing though that did come out of it is that Coronation St is back at 7.30pm, so that's a good thing."
Labour Party general secretary Chris Flatt says Labour raised issues with the BSA's decision at the time.
"The unique side of the law here is that you do have two bodies that can interpret the same piece of legislation."
He said the BSA's interpretation of the law seemed to rely on too narrow an interpretation of the rules.
"We feel vindicated for making the complaint."
The radio show was a new type of electioneering and Labour felt it was a serious matter to ensure the election period rules applied.
Flatt said it may be time for a review of how complaints were resolved.
That could include looking at whether matters needed to be referred to police and getting them dealt with in a more timely manner.
"Our concern was three months out from an election you're getting this high profile exposure and the rules are somehow not applying to this show because it's an 'election-free zone' and we argued the very nature of having a Prime Minister on an hour-long show interviewing his best friends as he called them, is inherently political."
Election campaigns moved quickly and it would be good to get the issues resolved before an election, he said.
A spokeswoman for Radio Live said they were surprised at the decision but would fully cooperate with police when they took the matter up.
They would not comment further as the matter was with police.
The Electoral Commission will release its full decision at 5pm today.