An independent report has found a lack of checks and balances around the way ministers appoint people to the boards of Crown entities.
Transparency International, a global organisation that measures corruption, has released papers that scrutinise the integrity of aspects of government in New Zealand.
The organisation says Crown entities such as Crown research institutes, district health boards and universities, are generally performing well.
But it says government ministers wield substantial power in making board appointments, and that has created a perception that appointments are a form of political patronage.
It suggests the Government improve transparency by establishing an independent commissioner, or widening the State Services Commissioner's role.
The Government has rejected the conclusions saying rigorous process is already in place for making ministerial appointments.
Duty minister Nikki Kaye said legislation governing Crown entities safeguards their operational independence.