Paul Ceglia claims that in 2003 he signed a contract with Mark Zuckerberg that entitles him to half the holdings of Facebook Inc.'s co-founder and CEO. He filed a lawsuit in district court in Buffalo, New York against the founder of the world's most popular social network.

Last week, Ceglia said he underwent a polygraph test in New York last week to prove his claim. Now he wants to Zuckenberg to undertake the same lie detector test. The test results were disclosed in court filings opposing Facebook's request that it be allowed to promptly inspect the original copy of the alleged contract and e-mails between Ceglia and Zuckenberg.

Ceglia has not shown the original contract to Facebook. Ceglia asked the court to order mediation between the parties. Zuckenber has insisted that Ceglia is an inveterate scam artist and says the contract was doctored. Zuckenberg claims that he only signed a contract with Ceglia for Web-development services for StreetFax.com when the former was still a Harvard University student. Closely held Facebook is estimated by Sharepost.com to be worth $69.3 billion.

This is not the first time Zuckenberg is facing a lawsuit claiming a piece of the company that is seen to be worth $100 billion when it goes public. Eduardo Saverin sued, claiming his shares of Facebook were diluted when the site's popularity grew sued, but later won an out-of-court settlement for undisclosed shares of Facebook and regaining his status as co-founder. Twins Cameron and Tyler Winklevoss, who claim Mark Zuckerberg stole their idea for the social networking site, have a lawsuit pending in a U.S. appeals court.