Prime Minister John Key says there is nothing new in documents showing the Government Communications Security Bureau knew in February last year that it had illegally monitored Kim Dotcom.
The Labour Party has obtained documents from the High Court in Auckland which reveal officials in the spy agency realised as early as February 2012 that they'd broken the law by intercepting communications from the internet entrepreneur and some of his associates.
But a series of emails between the officials and members of the police's Organised and Financial Crimes Agency also show they decided there was no need to take the matter any further.
Mr Key says the GCSB checked at the time and was wrongly told by its senior lawyer that the surveillance was lawful.
He says he was only told in September that it was illegal.
On his way into the House on Wednesday afternoon, Mr Key was asked by reporters whether the GCSB should have told him as early as February.
He replied that it was an operational matter and he is never involved in operational matters. He added, however, that a compliance review was in progress and that when a report was received, "I wouldn't be surprised if it indicates that there needs to be significant change."
Mr Key says the GCSB got it wrong in its surveillance of Mr Dotcom, but he doesn't believe it was malicious.
Robertson alleges a cover-up
The affidavits and emails obtained by the Labour Party include an affidavit from an unnamed GCSB officer stating that he learned on 22 February 2012 that Immigration New Zealand had told the police's Organised and Financial Crimes Agency Mr Dotcom and his family and another suspect and his family were residents.
That meant, he said, that the interceptions were not authorised under the GCSB Act.
Labour's deputy leader, Grant Robertson, says that raises serious questions about the whole operation.
"This is a combination of extremely sloppy behaviour, poor communication and a cover-up," Mr Robertson says, "and then New Zealanders are expected to believe that none of this was communicated to the Prime Minister.
"Now if that's true, someone has gone out of their way to make sure the Prime Minister didn't know."
Mr Robertson says the organisations should have done something as soon as they found out the men were residents. It is illegal for the GCSB to spy on New Zealand residents.
The United States is seeking the extradition of Mr Dotcom on copyright, money laundering and fraud charges.