National Party leader John Key says it is odd that a human rights report ended up in the media, but not in the hands of the government minister involved in the case.
The Office of Human Rights Proceedings is looking into a privacy complaint against National MP Paula Bennett, who as Social Development Minister released details of welfare assistance given to a single mother.
Last year, the Privacy Commissioner referred the complaint to the Human Rights Commission after failing to resolve the matter.
During campaigning in Hawke's Bay on Sunday, Mr Key said he finds it interesting that the document has found its way to the woman who laid the complaint and TV3 - but not to Ms Bennett.
"However that got there - that's for others to explain. But I find that rather interesting, when the very person the report is about actually hasn't got a copy of the report.
"This is about people's human rights - well, my minister has human rights as well."
Bob Hesketh, the director of the Office of Human Rights Proceedings, says he is seriously concerned the document has been obtained by a media outlet.
Mr Hesketh says he can unequivocally state that it did not come from his office.