Facebook‘s counsel asked courts to dismiss a case against founder Mark Zuckerberg on Monday, involving plaintiff Paul Ceglia, who claims he rightfully owns 50% of the multibillion-dollar company.

“Today’s motion proves what Facebook and Mark Zuckerberg have emphatically stated all along: this case is a fraud,” said Orin Synder and Gibson Dunn, representatives for Facebook and Mark Zuckerberg, in a statement. “The motion asks the court to dismiss this fraudulent lawsuit, and demonstrates that Ceglia has forged documents, destroyed evidence, and abused the judicial system in furtherance of his criminal scheme. Ceglia must be held accountable.”

Ceglia claims to have a contract with Zuckerberg, as well as e-mails promising the large stake in Facebook in return for helping Zuck get off the ground in 2003-2004. Facebook, however, calls this a “fraudulent shakedown” and says Ceglia is simply trying to extort money from a company that has come into success. Ceglia filed the suit in 2010 and in 2011 Facebook criticised him for forging documents.

Now, Facebook wants the case thrown out completely and refers to Ceglia as a “a career criminal and hustler”. It has presented a “treasure trove of evidence — much of which has never before [been] made public and comes from Ceglia’s own computers and e-mail accounts.” This new information includes e-mails between Zuckerberg and Ceglia that were not previously released, obtained by using cyber forensics.

The evidence also includes claims that a set of “Work for Hire” papers filed by Ceglia have “fresh” ink on them — ink that was only placed on the paper in the last two years. During a search of the document’s metadata, Facebook found Ceglia had made seven different attempts to backdate the document correctly before turning it in.

Facebook also alleges that Ceglia wrote his version of the Zuckerberg e-mails in a Word document, backdated by changing the computer’s time stamp. The company even says that some of Ceglia’s e-mails are a “historical impossibility”, including one sent on the morning of Facebook’s launch day. According to the social network, the actual Facebook website did not go live until the afternoon.

Facebook concluded its move to dismiss saying, “This case is his biggest hustle yet… From the beginning, Facebook recognised that its attorneys were not defending a lawsuit, but prosecuting a fraud.” — Meghan Kelly, VentureBeat