Broadcasting Minister Craig Foss says he is disappointed about what has happened at Television New Zealand's Maori and Pacific Unit.
TVNZ has begun an internal investigation into the unit, because leaked documents show some of its staff members have used company resources to carry out Labour Party business.
Maori and Pacific Unit general manager Shane Taurima resigned after it emerged he had been involved in a Labour Party hui in January.
Mr Taurima unsuccessfully contested the Ikaroa-Rawhiti candidacy for Labour last year and was considering seeking the candidacy for Tamaki-Makaurau.
TVNZ says it was a mistake to take him back after the Ikaroa-Rawhiti by-election.
Mr Foss says the controversy is not a good look for TVNZ, and he has been assured by its chairman that it will not happen again.
TVNZ will also review the editorial independence of the Maori and Pacific Unit during Mr Taurima's time as manager.
National Party MP Tau Henare says TVNZ must ensure the people employed in the future keep their political opinions to themselves.
Mr Henare told Morning Report he has always felt Mr Taurima was biased in interviews, though he cannot point to any specifics.
He says the issue goes deeper than a simple mistake and TVNZ staff must take a long hard look at themselves to avoid a reoccurrence.
"They have to take a good, hard look at themselves when they are in positions like that. The management have to take a good hard look at themselves when they're employing people, Mr Henare says.
"If you're working for the state, and it doesn't matter who the Government is, then you should not be peddling your own politics."
New Zealand First leader Winston Peters says many people in Maoridom will be disappointed about what has happened at TVNZ's Maori and Pacific Unit.
"The main thing here is that for Maori to perform professionally you've got to perform at the highest possible standards."
Mr Peters says he has a lot of time for Mr Taurima, who has always been professional on occasions he's had interviews with him but "the whole image does not look good".