Social Housing Minister Paula Bennett says her staff member did tell a journalist about a police investigation into the chairman of a marae that has been helping the homeless.
Labour's housing spokesman Phil Twyford said it was "a disgraceful abuse of power".
Prime Minister John Key says Social Housing Minister Paula Bennett should not have shared personal details about the head of an Auckland marae which is caring for homeless people.
But he is backing his under-pressure minister, saying he has "huge confidence" in her.
Mrs Bennett's office was last week accusedby Opposition MPs of trying to smear Te Puea Marae chairman Hurimoana Dennis.