Facebook CEO Mark Zuckerberg will testify in court on Tuesday, January 17 for a potentially explosive lawsuit that claims the Oculus VR startup he acquired for $2 billion was based on stolen technology.

The more than two-year-old suit against Facebook by game maker Zenimax has culminated with a public trial by jury in a Dallas court that began on January 9. Zenimax is seeking $2 billion in damages against Facebook, which is the amount the social networking giant initially paid to buy Oculus in 2014.

Representatives for Zenmiax confirmed to Business Insider that Zuckerberg will take the stand on Tuesday, followed by Oculus cofounder Palmer Luckey later in the week. The trial began on January 9; Oculus CTO and former Zenimax employee John Carmack was the first to testify on January 10.

Facebook tried to argue that Zuckerberg shouldn’t have to answer questions about his acquisition of Oculus, but the case’s judge overruled the request. Luckey’s testimony will be his first public appearance since he admitted to secretly funding a political group that created anti-Hillary Clinton memes in September.

“One of the biggest technology heists ever”

At the center of the lawsuit is Oculus CTO John Carmack, who previously ran a video game company within Zenimax called id Software and is best known as the mastermind behind video games like “Doom” and “Quake.”

Zenimax has accused Oculus executives of knowingly stealing its software and trade secrets through the hiring of Carmack and five of his employees from id Software. It claims that Carmack violated his employee agreement with Zenimax by sharing confidential information that Oculus then used as the basis for its VR software.

A lawyer representing Zenimax, Tony Sammi, went so far as to call Facebook’s acquisition of Oculus “one of the biggest technology heists ever” during opening remarks to the jury on January 10.

Facebook contends that Zenimax’s claims are without merit, and that Zenimax only filed the lawsuit because it passed on investing in Oculus before Facebook bought the company for $2 billion and an additional $800 million in employee retention payouts.

“Oculus and its founders have invested a wealth of time and money in VR because we believe it can fundamentally transform the way people interact and communicate,” an Oculus spokesperson told Business Insider. “We’re disappointed that another company is using wasteful litigation to attempt to take credit for technology that it did not have the vision, expertise, or patience to build.”

Zuckerberg, Luckey, Iribe, and other key Oculus employees are scheduled to testify during the remainder of the three-week trial. They will be asked about how Facebook came to acquire Oculus, the details of how the Oculus Rift headset was invented, and whether Carmack violated his contract with Zenimax. Prior to these testimonies, most of the case’s proceedings have been kept secret and under seal by the court.

This story originally appeared on Www.businessinsider.com. Copyright 2017