While Jean-Rene Fourtou and Barry Diller attempt to unravel some of the complexities in their relationship, Diller's USA Interactive has stepped into the melee accusing Vivendi Universal of trying to avoid tax payments of over $600m in conjunction with last December's sale of USA Networks to Vivendi Universal.

In a filing with the Securities and Exchange Commission (SEC), USA Interactive said Friday that Vivendi has stated it is not obliged to make such payments. Responding Sunday night, Vivendi Unviersal released a statement disagreeing with USA's "interpretation of the partnership agreement regarding Vivendi Universal Entertainment's (VUE) obligation to make payments in respect of taxable income allocated to USA's preferred interests in VUE."

When USAi made the sale to VUE it was paid via $2.5bn worth of preferred stock. According to USAi, VUE is bound to pay the taxes on what those shares yield.

The statement goes on to say "Various matters of the partnership agreement are currently the subject of review, discussion and negotiation between the parties.".

USA Interactive is the e-commerce business that Diller runs separately from VUE where he is CEO.