The Environment Minister says he isn't breaking any rules in his use of an apartment within the parliamentary precinct.

Newstalk ZB has put questions to Nick Smith over allegations a staffer in his office has been provided free accommodation in the apartment, in return for maintaining it.

In response, Smith's office has confirmed the Minister does lease an apartment in Bowen House for which he claims accommodation expenses.

But Smith occupies the apartment and has had family and friends stay in the spare room, in accordance with the rules.