Decision to keep him in his job had been a mistake in hindsight, says chief executive.
TVNZ chief executive Kevin Kenrick says the state broadcaster gave Shane Taurima a journalism or politics ultimatum when he was reinstated at TVNZ after his venture into politics last year and revelations of the extent of his involvement with Labour since then were "very disappointing".
A review team is now set to probe the extent of Mr Taurima's involvement with the Labour Party while he was working at TVNZ, involvement by other staff and any impact it had on the broadcaster's editorial work.
Mr Kenrick said TVNZ had sought commitments from Mr Taurima after his tilt for Labour at the Ikaroa-Rawhiti candidacy before restoring him to his role heading the department. "The key focus was to get him to make an explicit choice between journalism and politics, and to make commitments around that. We relied in good faith on those commitments."
Mr Taurima's solid 12-year record at TVNZ had been a factor in the decision to reinstate him.