Paul Ceglia's claim on Facebook may finally face the music.

Citing a wealth of forensic evidence, Facebook on Monday filed a motion to dismiss what it labelled a “shakedown” lawsuit by Paul Ceglia, who sued the world's biggest social network in June 2010 for breach of contract -- claiming a document entitles him to ownership of 85 percent of the company.

"Today's motion proves what Facebook and Mark Zuckerberg have emphatically stated all along: this case is a fraud,” said Orin Snyder, partner with Gibson Dunn and the attorney for Facebook and Mark Zuckerberg.

Along with the motion, Facebook filed what it described as a “treasure trove” of evidence attacking the authenticity of the contract and a series of emails between Zuckerberg and Ceglia.

“The motion ... demonstrates that Ceglia has forged documents, destroyed evidence, and abused the judicial system in furtherance of his criminal scheme. Ceglia must be held accountable," Snyder said.

"Ceglia must be held accountable."

- Orin Snyder, attorney for Facebook and Mark Zuckerberg

Digital forensics experts with Stroz Friedberg hired by Facebook uncovered what they call the authentic contract between Ceglia's company StreetFax and Zuckerberg on hard drives submitted by Ceglia as evidence. That contract dates to 2003 -- before the creation of the social network.

A document filed in court Monday details the company's findings.

“Stroz Friedberg did find a signed copy of an April 28, 2003 contract between Mr. Ceglia and Mr.Zuckerberg, entitled ‘STREET FAX,' concerning Mr. Zuckerberg's work on the StreetFax project,” that document reads. “Stroz Friedberg found direct and compelling digital forensic evidence that the documents relied upon by Mr. Ceglia to support his claim are forged.”

“Stroz Friedberg also found what it believes to be the authentic contract between Mr. Ceglia and Mr. Zuckerberg. That contract contains no references to Facebook.”

That same document was also recovered from the records of law firm Sidney Austin, where Ceglia emailed it in early 2004, the document says.

Facebook also introduced in court additional proof that the document alleging part ownership in Facebook is a fake: testimony from a forensic chemist and a documentation authentication expert, both of whom called the contract bogus.

A spokesman for Mr. Ceglia declined to comment until his attorneys had more time to read the motion, the Wall Street Journal reported.

Ceglia originally sued for breach of contract, alleging a Work for Hire contract between himself and Mark Zuckerberg -- dated April 28, 2003 -- gave Ceglia a multi-billion-dollar ownership interest in Facebook.  Ceglia claims to have forgotten that he had the contract for 7 years and then stumbled across it when he was looking through his files.