Facebook is asking a federal judge to throw out the lawsuit by Paul Ceglia claiming that he's entitled to half of the company.
It says it's recovered 200 emails between Ceglia and Mark Zuckerberg from Harvard University servers - and they're nothing like those previously provided by Ceglia.
According to the Wall Street Journal, Zuckerberg's lawyers have written to the court, calling the mails a 'fabrication' and the lawsuit 'a fraud and a lie'.
Ceglia has been arguing that he owns as much as 84 percent of Facebook, on the basis of a contract purportedly signed in 2003. It gives him 50 percent of the company, plus one percent more for every day the site failed to launch after January 1, 2004.
Facebook's lawyers also say they've finally found the original contract, setting up a site called StreetFax, on which they say Ceglia's forged version is based. The company hinted as much last summer.
Ceglia's contract, they say, is a doctored version of the first page of the StreetFax contract, tacked on to the second page of a Work for Hire contract that Zuckerberg genuinely did sign.
The ink used for handwritten amendments is claimed to be shown to be less than two years old, and the paper aged by hanging it in the sum with clothespegs.
Ceglia's lawyers say they aren't giving up yet - though they sound less than totally confident.
"The Federal Rules of Evidence say a jury should weigh the evidence in this case, including experts’ declarations in Mr Ceglia’s favor about the authenticity of his contract with Mr Zuckerberg," one told Fox News.
"Mr Ceglia deserves his day in court, where the jury will resolve this dispute over the ownership of Facebook."