Lawyers for Zennström and Friis don't mince words in their latest salvo -- just as they didn't in their earlier lawsuit, which accuses Volpi of lying, stealing and bad faith. On Wednesday, the pair asked the court to bar Volpi from using knowledge or confidential information he obtained at Joost to benefit the Skype deal. The consortium trying to buy Skype also includes Silver Lake Partners and Andreessen Horowitz, the investment firm of Marc Andreessen, the billionaire co-founder of Netscape.

"This action arises out of the acts of a faithless fiduciary, defendant Michelangelo Volpi, who, despite being the chief executive and Chairman of Joost, embarked on a systematic scheme to breach his fiduciary duties and promote his own self-aggrandizing campaign to become the next chairman of internet telephony leader Skype Inc." Ouch.

Last month, the pair sued Volpi and others through two companies they control, Joltid Ltd. and Joost N.V., in a Delaware court. The suit charged Volpi, the former chief executive officer of Joost -- which Zennström and Friis also founded -- with breaching his fiduciary duty. It also accused Volpi of allegedly stealing confidential information in an effort to seal the eBay deal for a consortium of prominent investors trying to buy Skype.

Last summer, Volpi became a partner at Index Ventures -- a member of the consortium -- after leaving Joost as the chief executive. He remained as chairman of the video startup. But, Friis and Zennström kicked him to the curb after they found out about his alleged backroom shenanigans.

The litigious duo had earlier filed a suit in Northern California district court seeking an injunction against Skype, which they founded but later sold to eBay (EBAY). The suit also sought statutory damages that they claim are accruing at an eye-popping rate of "more than $75 million daily." The latest filing can be found here.

Zennström and Friis had maintained a copyright claim to Skype's peer-to-peer calling technology, even after they sold the company to eBay in 2005. Last month, eBay announced that a private consortium led by Silver Lake would pay $1.9 billion in cash for Skype, which eBay expects to earn revenue of $600 million this year.

The giant online auctioneer would retain a 35 percent equity investment in Skype. It had said it wanted the deal, which values the company at $2.75 billion, to close before the end of the year.