John Carmack, seen here wearing an early prototype Oculus Rift headset.

ZeniMax Media, the parent company of both Bethesda Softworks and Id Software, says it will prove at trial that John Carmack and others at Oculus stole trade secrets to “misappropriate” virtual reality technology that was first developed while Carmack was working at Id Software. What’s more, ZeniMax is now accusing Oculus of “intentional destruction of evidence to cover up their wrongdoing.” Mark Zuckerberg, CEO of Oculus parent company Facebook, is scheduled to respond to those accusations in testimony starting tomorrow, according to a report by Business insider.

“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 (VR) intellectual property,” ZeniMax wrote in a statement given to Ars.

“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.”