Social Housing Minister Paula Bennett has refused an offer of resignation from the press secretary who told a journalist that a marae leader was under police investigation.
Ms Bennett today faced further questions about the leak, which she said was a "grave error of judgment" by her staff member.
Pressed by Labour MP Kris Faafoi during a scheduled appearance before a select committee in her role as State Services Minister, Ms Bennett said she had no idea the information had been passed on, until confronted by media yesterday afternoon.
"I do not think that she tried to deliberately smear. I do not think that she was trying to deliberately undermine anyone, and I think it was in the context in a conversation about something else, and then at the end it came up.
"She deeply, deeply regrets it. And I can't apologise enough."
Ms Bennett has phoned and apologised to Te Puea Marae chairman Hurimoana Dennis, a police inspector and iwi liaison officer.
Mr Dennis has been leading efforts to help the homeless, and Mrs Bennett and the staff member met with him last Friday to discuss those measures and what Government support could be made available.
During that private meeting Mr Dennis disclosed that he was subject to a police investigation.
Later that day, the staff member returned the call of a One News reporter, based outside of the Parliamentary press gallery. It was during that conversation that the police investigation was mentioned.
On her way into question time yesterday, Ms Bennett was asked by Radio New Zealand about her staff member passing on the private information.
Labour's housing spokesman Phil Twyford has said it was unthinkable that Mrs Bennett's staff member would go "rogue", without her knowledge.
Speaking to media after the select committee appearance today, Ms Bennett said she was not aware that the information had been passed on until yesterday afternoon.
She said she did not know if the One News reporter already knew about the police investigation.
"I sought assurances as to whether or not it was in any way intended to smear him or for her comments to be made public, and I'm assured it wasn't."
There would be no employment consequences for the press secretary, Ms Bennett said: "We are moving on."
Marae spokeswoman Moko Templeton has told the Herald that Mr Dennis had the full support of the marae board. She felt the leaking of the details about Mr Dennis was a smear.
Police are investigating Mr Dennis' handling of a case in which he intervened on behalf of a teenager who was in a sexual relationship with a 15-year-old girl.
The investigation follows a complaint about Mr Dennis' handling of the case, and is not a criminal investigation of him personally.
The Herald understands Mr Dennis intervened on a personal basis outside working hours on behalf of a 16 or 17-year-old youth, known to him through family friends, who was in a sexual relationship with a 15-year-old girl.
Mr Dennis helped arrange for the youth to move to Australia. He subsequently returned to New Zealand, and his family complained about Mr Dennis' involvement.
Labour has accused Mrs Bennett of "having form" on leaking details. In 2009 she provided the benefit details of two beneficiaries to the Herald after they criticised her decision to scale back the Training Incentive Allowance.
She subsequently stood by that action, and today said she had always been "totally straight-up".
"My form is to be, if anything, a little bit in people's faces and open about what I'm doing."