Police Minister Judith Collins says continuing speculation about a senior officer refusing to take a breath test at his house is damaging public trust in police.
It has been reported that the officer involved is Superintendent Graham Thomas, who is in charge of the police prosecutions unit.
However, police have refused to confirm the officer's identity.
Police say the officer was within his rights to decline a breath test when officers visited him at his Wellington home in December.
Ms Collins told Parliament on Tuesday she was first informed by police in December there had been an incident involving a senior officer in Wellington.
She says after an investigation found insufficient evidence for a drink-driving charge, police began an employment process.
Ms Collins says she has been assured that police are following procedures "by the book", and continuing speculation has damaged public trust in the police and undermined their good work.
The minister says she cannot comment further on an employment matter.
Labour MP Clayton Cosgrove says Ms Collins needs to assure the public that correct procedures have been followed.
Police Commissioner Howard Broad is due to appear before Parliament's law and order select committee on Wednesday