Comments by Serious Fraud Office head Adam Feeley in a leaked email have been referred to the State Services Commission by the minister responsible for the office.
SFO staff reportedly celebrated progress in a case against Bridgecorp Finance by drinking a bottle of Bridgecorp's own champagne.
Mr Feeley's email, which was leaked to The New Zealand Herald, invites staff to celebrate the office's success with the bottle of champagne and more bubbles he would provide.
The newspaper quoted him as saying the champagne was left in an office after Bridgecorp's directors quit when their company was liquidated.
Mr Feeley told the paper he later worked in that same building and took the bottle because he felt there was no better claimant to it.