The legal team for Paul D. Ceglia, who claims to own at least 50 percent of the social network, is expected Wednesday to present its discovery plan in court related to evidence in the case. It is common in lawsuits for both sides to seek documents from the other and fight it out with a judge when there are disputes.

If the plan is approved, it could empower Ceglia's lawyers to look at vast amounts of information about the early workings of Facebook and Zuckerberg -- an unwelcome prospect for a company planning to raise some $5 billion in an IPO later this year.

"We look forward to examining records from computers that Mr. Zuckerberg used when he was a freshman at Harvard and other records that will help answer questions about the ownership of Facebook," Sanford Dumain of the New York City law firm Milberg LLP said in a statement.

"We hope that the court will rule that the time has come for that process to begin," he added.

Milberg is to take up Ceglia's cause in court. Its entry into the case is significant because it's a high-powered law firm known for its involvement in high stakes lawsuits.