Kim Dotcom says John Key is lying

Kim Dotcom claims Prime Minister John Key is not telling the truth about what he knew before the German Internet giant's arrest on copyright charges.

Speaking on TVNZ's Q+A, Dotcom said he believed Key was lying about what he knew and he had evidence to show that.

"He is running around naked and telling people he has clothes on. Everyone can see he's naked. It doesn't make any sense. I know for a fact John Key knew before January 19.

"It's going to be a topic in our court hearings. I don't want to reveal too much. But I know. And for him not to be honest and upfront about it - to me there is really only one reason. That's the political interference element that could stop the full extradition procedure.

"If we can show the government here has had an active role in the magnitude of this whole case and had a proactive rather than reactive role to impress the United States government, well you know, there you have it. It's a monster issue."

Asked by interviewer Paul Holmes if he believed Key lied, Dotcom replied "yes".

Asked if he had the evidence to prove that, he also replied "yes".

Key has repeatedly said he had never heard of the German millionaire till he was briefed ahead of a raid on Dotcom's Coatesville mansion in January.

A spokeswoman for Key later issued a statement saying: "The Prime Minister stands by his earlier statements that the first he knew of Kim Dotcom was on 19 January 2012."

Dotcom is facing extradition to the US on copyright charges related to his company Megaupload.