PM challenges Nicky Hager to release emails

Prime Minister John Key is challenging Nicky Hager to go public with the emails he used for his book Dirty Politics.

The Prime Minister has challenged Nicky Hager to go public with the emails at the heart of his book. Source: 1 NEWS

Mr Key says Mr Hager's accusations, like those against Judith Collins, who Mr Key says is in the clear, are falling flat.

"He should knock his socks off and release anything he wants because most of the assumptions are now dissolving before his eyes," says Mr Key.

Earlier today Mr Key said he's happy for the police or other agencies to take a closer look at allegations in Nicky Hager's book Dirty Politics.

"The only dirty politics here is from the left," John Key told ONE News.

The Green Party says it will lodge complaints with the Parliamentary Service, the Inspector-General of Intelligence and Security and the Privacy Commissioner and co-leader Metiria Turei says the issue needs to be taken seriously and properly investigated.

"I can guarantee that this has not happened in our office," Ms Turei says. "It is one of the most serious allegations we've seen in New Zealand politics for some decades."

The Prime Minister is ruling out running any inquiry of his own but Mr Key says the Greens are free to do whatever they like and if they want a royal commission "they should go for it 100%".

The Green Party will also lodge a number complaints with police, including one alleging Justice Minister Judith Collins leaked private information, and another one about allegations in Mr Hager's book that sensitive documents were declassified in order to be used as political smears.

Ms Collins has dismissed claims she collaborated with right-wing blogger Cameron Slater and Mr Key has accepted her assurances.

Labour is also talking to its lawyers.

"I know nothing that is equivalent to this. What I can tell you is that the Prime Minister has some very serious questions to answer," leader David Cunliffe says.