Megaupload founder Kim Dotcom is set to launch a new file-sharing website and music service before the end of the year, despite spending much of 2012 fighting US prosecutors who shut down his first site in January.

Kim Dotcom

The file-sharing site that Dotcom started in 2005 was one of the most popular online sites before US prosecutors shut it down and filed racketeering charges against Dotcom and six other Megaupload principals in January.

A citizen of New Zealand, Dotcom is accused of earning millions of dollars from his Megaupload site through providing users with access to copyrighted material like films and music. US authorities claim he owes the entertainment industry some $500m (£312m).

Dotcom, 38, said that the new websites - "New Mega" and "Megabox" - are almost complete

"Quick update on the new Mega: Code 90% done. Servers on the way. Lawyers, Partners & Investors ready. Be patient. It's coming," he tweeted.

Asked by one Twitter user if he was nervous that what happened to Megaupload could happen to New Mega, Dotcom replied: "That will be impossible. Trust me."

The original Megaupload website was closed down by the FBI in January, coinciding with a high-profile raid of Dotcom's New Zealand mansion. Armed police arrived by helicopter, stormed his house and found Dotcom in a panic room.

In September it was revealed that Dotcom and an associate were monitored by the New Zealand authorities. The revelation was quickly followed by an apology by Prime Minister John Key after it was revealed that spying on New Zealand citizens is illegal.

"Of course I apologise to Mr Dotcom and I apologise to New Zealanders," Key said.

Key said that New Zealanders had a right to be protected by the law and that the government had "failed to provide that protection to them".

Megabox

The upcoming Megabox service will allow users to download music free in exchange for accepting advertisements - similar to how the free version of Spotify works.

Dotcom, aka Kim Schmitz, said that 90 percent of revenue generated by the site will go to the artists and the service will be a legitimate way of "unchaining artists and fans" to do business with each other with no need for a middleman.

A video posted by Dotcom on YouTube shows a team of developers working on Megabox with clips of what the new service will look like, how it will interact with social networks such as Facebook and Twitter, and how users can upload their own music to it.

Dotcom's ability to seemingly hire employees and create a new business has raised questions with some legal experts. Bail restrictions, which prevented access to the internet and froze millions of dollars in bank accounts, were lifted.

Jennifer Granick, the director of civil liberties at the Stanford University law school's Center for Internet and Society, said Dotcom's case marks the first time the US has attempted to hold somebody criminally liable for copyright infringement committed by others. She said prosecutors were pushing at the boundaries of the law.

"It makes the substantive underpinnings of the case highly questionable, legally," Granick said. "It's a novel case."

Dotcom's extradition hearing is scheduled for March.