Mark Zuckerberg
Facebook CEO Mark Zuckerberg holds a pair of the touch controllers for the Oculus Rift virtual reality headsets on stage during the Facebook F8 conference in San Francisco Reuters/Stephen Lam

Facebook CEO Mark Zuckerberg is set to testify in Dallas, Texas, in an ongoing lawsuit that claims Oculus, the VR company acquired by the social media giant in 2014, is based on stolen technology. ZeniMax Media, the parent company of Bethesda, Doom developer id Software and Dishonored creator Arkane, alleges that Oculus CTO John Carmack stole data from the company before he left in 2013.

The public jury trial began on 9 January with ZeniMax seeking $2bn (£1.6bn) in damages - the amount Facebook paid to buy Oculus in 2014. While Facebook's legal team argued that Zuckerberg should not have to answer questions regarding his company's acquisition of Oculus, the judge dismissed the argument.

ZeniMax filed the lawsuit against Oculus in 2014 and its founder Palmer Luckey accused the VR company of misappropriating trade secrets in the development of the Oculus Rift headset and wrongfully benefiting from years and "tens of millions of dollars" worth of ZeniMax research.

ZeniMax also accused Carmack and "others" of improperly providing "key technology" to Oculus. Oculus denied the claims and said it will disprove the allegations.

In a revised 2016 complaint, ZeniMax claimed that Carmack breached his employee agreement with the company after he "copied thousands of documents from a computer at ZeniMax to a USB device" and never returned them after his employment was terminated. The complaint also alleges that he returned to ZeniMax's premises after his employment was terminated "to take a customised tool for developing VR Technology belonging to ZeniMax that itself is part of ZeniMax's VR Technology" without the company's permission.

The suit claims that Luckey is not the inventor of the virtual reality technology, saying he "lacked the training, expertise, resources or know-how to create commercially viable VR technology". Instead, Oculus spread a "false and fanciful story" to the press, at CEO Brendan Iribe's direction, that Luckey was the inventor of VR technology who created it in his parents' garage, the suit alleges.

Alleging that his computer programming skills were "rudimentary", the complaint says he "increasingly and falsely held himself out to the media and the public as the visionary developer of the Rift's VR Technology, which had actually been developed by ZeniMax without any substantial contribution from Luckey".

The revised suit also included Facebook asserting that it went ahead with the merger with "full awareness" of the non-disclosure agreement made by Luckey and alleged misrepresentations made by Oculus officials.

During opening statements on 10 January, Tony Sammi - one of ZeniMax's legal representatives - called Facebook's acquisition of Oculus "one of the biggest technology heists ever".

"With the start of the trial of our case in Federal District Court in Dallas against Defendants Facebook, Oculus and its management, ZeniMax and id Software welcome the opportunity to present substantial evidence of the defendants' misappropriation of our Virtual Reality intellectual property," ZeniMax said in a statement to Polygon. "That evidence includes the theft of trade secrets and highly confidential information, including computer code. ZeniMax will also present evidence of the defendants' intentional destruction of evidence to cover up their wrongdoing. ZeniMax and id Software are the visionary developers of breakthrough VR technology, and look forward to the vindication of our claims."

Facebook and Oculus, however, have maintained that ZeniMax's claims are baseless.

"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."

During the three-week trial, Luckey, Iribe and other Oculus employees are also scheduled to testify where they will be asked how Facebook acquired Oculus, details about the development of the Oculus Rift headset and if Carmack did violate his contract with his former employer ZeniMax, the publication reports.

Meanwhile, Zuckerberg wrote in a Facebook post that the first state he is visiting as part of his personal goal to visit every US state this year is Texas. "I'm here in Dallas for work, but I'm also taking time to meet members of our Texas community over the next few days as part of my Year of Travel challenge."