The founders of Skype are suing the investment company that is buying the internet telephony service from current owner eBay, demanding billions in compensation for copyright infringement.

In a move that's highly likely to disrupt the $1.9 billion buy-out, Joltid Ltd, a Swedish firm owned by Skype founders Niklas Zennstrom and Janus Friis, claims peer-to-peer technology owned by Joltid, and not eBay, is being used in a breach of license with every download of the Skype software.

Joltid and Skype are currently in a legal dispute in Britain over software rights, but this brings the fight to the new owners, and the American court system with the lawsuit filed in Northern California.

"The Skype companies have continued to infringe Joltid's copyrighted works on a massive scale. Each day that the Skype Companies continue to make available its Internet telephone software for download, Skype users download Joltid's copyrighted works approximately six times per second" says Joltid, claiming damages of $75 million a day.

"Their allegations and claims are without merit and are founded on fundamental legal and factual errors", eBay said in a statement.