Megaupload founder fighting extradition from New Zealand says he is determined to beat American authorities at their 'foul game'

From a semi-rural suburb north of Auckland, Kim Dotcom is mounting an increasingly belligerent counter-offensive against US authorities' efforts to prosecute him over his now defunct Megaupload file storage site.

In an interview with the Guardian, Dotcom, who remains on bail in Coatesville, New Zealand, awaiting an extradition hearing, declared himself to be in "fighting mood" and eager to refute a "case built on malicious conduct".

The charges against him, he said, were part of a "foul game" on the part of the US government, and that funds permitting, "I am going to war."

Dotcom is being sought by the US to face criminal copyright charges related to the MegaUpload file storage site, which at its peak amounted for an estimated 4% of all internet traffic.

Prosecutors allege he and his co-accused associates were complicit in and encouraged the distribution of copyright-protected films, music and other material.

The German-born New Zealand resident's remarks, in an email interview with the Guardian, follow Tuesday's announcement that his extradition hearing, scheduled to begin in less than a month, has been put back until April next year.

On Wednesday morning Dotcom laid down the gauntlet to the US department of justice, offering to travel to the US under his own steam and faces charges – with conditions. "Hey DOJ," Dotcom said on his Twitter account, "we will go to the US. No need for extradition. We want bail, funds unfrozen for lawyers and living expenses."

He told the Guardian that the offer was genuine but he was not holding his breath. "Considering the way the US government has conducted their case and the way I was treated, I never expect to get a fair trial in the United States," he said.

"We are not expecting to hear back regarding the offer and I remain committed to fighting extradition in New Zealand."

Dotcom has 22 lawyers working on his case in different countries. He says he faces a mounting legal bill, exacerbated by the rescheduled extradition hearing.

The delay was made inevitable by the need to first resolve a clutter of outstanding legal disputes. The Auckland high court ruled last month that the January raid on Dotcom's mansion was conducted illegally, that evidence has been wrongly withheld from his legal team, and that the FBI had inappropriately cloned hard drives and taken them from the country.

An earlier district court instruction for the FBI to provide copies of cloned drives to Dotcom's lawyers is expected to be appealed, and other decisions may also be taken to higher courts.

Those who interpreted the postponement as a victory for Dotcom were mistaken, he told the Guardian. "People might think it's good news. But it's not. Justice delayed is justice denied. And that's the foul game the US government is playing. They have terminated my business without a trial. They have frozen my assets without a hearing.

"They are appealing the decision of a New Zealand judge who has ordered the US government to provide evidence before the extradition hearing starts."

US authorities had dragged other countries into a vendetta driven by special interests, he said. "They have been misleading the Hong Kong and New Zealand government to destroy a legitimate business and 220 jobs by telling them stories about child pornography and terrorist propaganda on Megaupload," he said.

"This whole case is built on malicious conduct. It is a stillborn case and everyone can see it. I am in a fighting mood and if I get my assets unlocked or somehow find funding to defend myself I am going to war."

The Megaupload founder last week alleged that the pursuit of Dotcom was directly ordered by the US vice-president, Joe Biden, at the behest of Hollywood studio executives – a claim the Motion Picture Association of America has rejected.

Next in Dotcom's sights is Biden's boss, in a rather more colourful medium. Dotcom, who has been recording an album with the help of Black Eyed Peas producer Printz Board at studios belonging to Crowded House's Neil Finn, is expected to release a new song and video this week pointing the finger directly at Barack Obama. The song reportedly includes the lyrics ""We must oppose / those who chose / to turn innovation into crime".

The track, Dotcom wrote in an email to the Guardian, would mark "the birth of a powerful movement and CHANGE".