Tyler and Cameron Winklevoss are attacking Facebook on a new legal front after opting not take their California case to the US Supreme Court.
The twin brothers and fellow ConnectU founder Divya Narendra revealed plans to rev up litigation in Massachusetts accusing Facebook of duping them in a deal they made in a lawsuit charging that Mark Zuckerberg stole their idea.
Lawyers for the Winklevosses notified a federal court in Boston on Thursday that they wouldn't appeal a failed California case to the Supreme Court, clearing the way to proceed in a separate lawsuit idling in Massachusetts.
The filing indicated that the Winklevosses intend to commence a "discovery" process aimed at uncovering whether Facebook suppressed evidence while negotiating a settlement with the ConnectU founders.
"These are old and baseless allegations that have been considered and rejected previously by the courts," Facebook attorney Neel Chatterjee said in a statement.
The twins have argued that Facebook held back information about the estimated value of the California-based social networking firm while reaching a $65 million settlement with the brothers.
The twins inked a settlement two years ago that got them $20 million in cash and $45 million worth of stock valued at $36 per share.
The value of that yet-to-be-issued stock has skyrocketed along with Facebook's estimated market value.
The brothers challenged the settlement, which was supposed to be confidential, on the grounds that Zuckerberg suckered them during settlement talks by not revealing Facebook internally valued the stock at $9.
The lower figure would have resulted in the Winklevoss twins getting many more shares.
Lawyers filed legal paperwork on Wednesday saying that the twin brothers will not ask the top court in the nation to overturn a decision the US 9th Circuit Court of Appeals made siding with Facebook.
The US 9th Circuit Court of Appeals in May rejected a bid by the identical twin brothers to have a full panel of 11 judges second guess a ruling made by a three-justice panel.
The three-judge panel said that litigation in the case "must come to an end" and threw out the bid by the Winklevosses to review the settlement.
Explore further: NBCUniversal settles with unpaid interns for $6.4M