ZeniMax has filed a legal notice against id Software founder John Carmack, accusing him of taking "ZeniMax's intellectual property with him to Oculus," according to The Wall Street Journal.
The firm claims Carmack took software he was developing while at id Software with him when he left the firm he co-founded for Oculus VR.
Carkmack took to Twitter to state that while ZeniMax may "own the code" he wrote, "no work ever done has been patented.
"No work I have ever done has been patented," he said. "Zenimax owns the code that I wrote, but they don't own VR."
While Oculus is denying the claim, ZeniMax sent a formal legal notice to the firm asking it to draw up a licensing agreement with it, or ZeniMax will take the company to court.
The claim also states that Oculus VR boss Palmer Luckey was aware of property owned by Zenimax was in-house and acknowledged said property in writing.
A spokesman for Oculus told the Wall Street Journal that the situation was "unfortunate, but when there's this type of transaction, people come out of the woodwork with ridiculous and absurd claims."
"We intend to vigorously defend Oculus and its investors to the fullest extent," Oculus continued.
It is unknown at present whether Facebook was aware that ZeniMax was in the process of seeking compensation for its intellectual property developed with the Oculus Rift by Carmack when it made the $2 billion deal.
ZeniMax issued a statement to WSJ noting it had "sent formal notice of its legal rights," and that it "believes it is necessary to address these matters now and will take the necessary action to protect its interests."
According to the report, ZeniMax has been seeking compensation from Oculus since August 2012, after Carmack was sent an early prototype of Oculus Rift by Palmer Luckey.
Carmack has demonstrated his modified version of the headset earlier that year during E3 that year, which ZeniMax claims was the "template for Oculus's Rift headset," according to the WSJ. Carmack mentioned at the convention that he created new software for the headset in order to make it a "workable product."
In February 2014, ZeniMax requested that Carmack to disclose any VR inventions created while working at id. Come April 18, ZeniMax contacted Oculus's lawyers as well as Facebook's general counsel, Colin Stretch stating: "It was only through the concerted efforts of Mr. Carmack, using technology developed over many years at, and owned by, ZeniMax, that Mr. Luckey was able to transform his garage-based pipe dream into a working reality."