Billy Mitchell, the former Donkey Kong and Pac-Man high-score champion made famous in the 2007 film The King of Kong, has threatened legal action against the sanctioning bodies who threw out all of Mitchell’s high scores in April 2018 after finding that two were illegitimate.

This week, lawyers for Mitchell sent a letter to Twin Galaxies and Guinness World Records demanding that both “retract their claims against Billy Mitchell” and restore the scores to their world record leaderboards, where Mitchell had been a fixture since the early 1980s. Attorneys made the same demand of Guinness World Records, which uses Twin Galaxies as its source for the video game high score records it recognizes.

At issue is the April 12, 2018 finding by Twin Galaxies, after a three-month investigation and deliberative process, that the gameplay in two million-point scores Mitchell claimed for Donkey Kong were not produced by original, unmodified arcade hardware. The implication in that finding is that Mitchell used an emulator running the game to produce the scores, and emulators allow different control schemes, display setups, and even the means to cheat or manipulate a score or performance.

Of the two scores that Twin Galaxies determined were not set on original arcade hardware, one was the 1,047,200 shown in the climactic moment of The King of Kong, when Mitchell snatches back the world record from rival Steve Wiebe with a videotaped submission sent in at the last moment. One of the scores thrown out, although Twin Galaxies made no determination as to its source platform, was a 1,062,800 set July 31, 2010, and previously acknowledged as the first million-point game in Donkey Kong history.

The challenge to the authenticity of Mitchell’s performance began at the end of 2017, in the Donkey Kong Forums, which also maintains several leaderboards for the game. An analysis there pointed out several technical disparities between the footage shown on Mitchell’s tape and how a natively rendered game performs, frame by frame. The allegation made at Donkey Kong Forums is that Mitchell had used an emulated version and replay footage to represent a continuous, authentic attempt. Twin Galaxies began its own investigation in January 2018.

The letter to Twin Galaxies alleges that it defamed Mitchell, both in its findings and in later posts to their website. In banning Mitchell, Twin Galaxies also vacated records that were not in question, and banned Mitchell from further participation in their leaderboards. One of Mitchell’s records thrown out was a “perfect score” in Pac-Man (reaching the maximum number of points available in its 255 levels)/ Mitchell’s attorneys say Twin Galaxies implied that score was tainted by cheating, too.

Guinness, say the lawyers, cited that disqualification in its 2019 Gamers Edition compilation of records in saying that Mitchell’s “submitted scores were obtained while using [the emulator] MAME,” which the attorneys take to mean as applying to all of Mitchell’s scores, from 1982 to present day. They say that is factually incorrect and also impossible, as MAME was created in 1997. “Guinness World Records never conducted an investigation into Billy Mitchell’s Pac-Man records,” the letter says.

The letter also alleges that Twin Galaxies “did not provide Billy Mitchell fair opportunity to provide evidence to prove his innocence,” and that “specific evidence was accepted, while evidence of equal stature was rejected.” The letter attached a 156-page package of counterclaims, signed statements and other materials presenting Mitchell’s side of the case. The documents can be found through a thread posted to Reddit’s speedrunning community.

Mitchell’s attorneys gave Guinness and Twin Galaxies two weeks to issue a retraction, “or we will resort to legal recourse.” It demanded Guinness conduct its own investigation, using Mitchell’s evidence package; Guinness “hiding behind its partnership with Twin Galaxies will be perceived as a refusal of this retraction request,” the lawyers write.

Polygon has reached out to representatives of Twin Galaxies and Guinness World Records and will update with any reply or comment received.