Authorities are seeking to have the Ukrainian owner of the file-sharing website KAT extradited to the US over alleged fraud and copyright infringement.
The owner of file-sharing website KAT has been indicted in the US for copyright infringement related to the distribution of more than $US1 billion ($A1.34 billion) worth of movies, video games, music recordings and other content.
Artem Vaulin, 30, of Ukraine, was arrested in Poland and US officials want him extradited to face charges that include conspiracy to commit criminal copyright infringement and conspiracy to commit money laundering, according to lawyers for the US District Court for the Northern District of Illinois.
US officials allege that KAT, which operates in about 28 languages, has a net worth of more than $US54 million ($A72.23 million) and illegally made available for download movies that were still in theatres such as Independence Day: Resurgence and Finding Dory, the complaint stated on Wednesday.
The indictment stated that for financial gain the peer-to-peer file-sharing website, also known as Kickass Torrents, distributed since 2008 copyrighted works such as this year's film Captain America: Civil War.
Justice officials and artists' groups have gone after other websites that provided venues for file sharing, such as Napster and Megaupload. The founder of Megaupload, known as Kim Dotcom, is fighting extradition to the United States and has denied allegations that his site has cost film and record companies more than $US500 million ($A668.76 million) in revenue.
"Copyright infringement exacts a large toll, a very human one, on the artists and businesses whose livelihood hinges on their creative inventions," US attorney Zachary Fardon said.
"Vaulin allegedly used the internet to cause enormous harm to those artists," Fardon said, adding KAT relied on computer servers around the world due to efforts to halt illegal file sharing.
There was no legal representation listed for Vaulin in any court docket, a US Department of Justice spokesman said. The company could not be reached through websites, which were experiencing outages, and there was no immediate response to a request sent to KAT through social media.
One of the domains operated by KAT, Kat.cr, was the 70th most popular website in the world, according to monitoring firm Alexa.