Cabinet will today discuss details of an inquiry into the appointment of the new Deputy Police Commissioner.

Concern has been raised about Wally Haumaha, because of comments he made about the Louise Nicholas rape case back in 2004.

At the time he said the allegations against fellow police were nonsense.

State Services Minister Chris Hipkins says Cabinet will consider the terms of reference of an inquiry into his appointment today.

"There's a need for the public to have reassurance that the process followed was robust, to understand if any concerns about that process have come to light subsequently," he said.

"And that's the nature of the discussion I think we'll have at Cabinet."

The Acting Prime Minister, Winston Peters, is currently suing Peter Hughes, the State Services Commissioner, over alleged breach of privacy over the leaking of his superannuation payment.

But Hipkins doesn't think that will impact on the inquiry process.

"I've had a conversation with the Acting Prime Minister about it, I've had a conversation with the State Services Commissioner about it. I think both of them are approaching this in an incredibly professional manner," he said.