It is estimated that establishing the Criminal Cases Review Commission will cost around $2.3 million, Justice Minister Andrew Little says.

In response to a parliamentary written question from National Deputy Leader Paula Bennett, Mr Little has said once established, the annual operational expenditure of the Commission is estimated to be approximately $4 million.

Decisions on levels of funding are yet to be confirmed.

The Criminal Cases Review Commission Bill was introduced to Parliament by Mr Little on 27 September 2018. It is currently before the Justice select committee.

The Commission's purpose will be to review convictions and sentences and decide whether to refer them to the appeal court. This will replace the power currently exercised by the Governor-General under section 406 of the Crimes Act 1961.

The Commission will be established as a new independent Crown entity, with a membership of no fewer than three but no more than seven Commissioners.