A feud brewing between two of the nation's biggest beer companies has spilled out into court.
The lawsuit, filed Thursday in the United States District Court for the Western District of Wisconsin, cites a 60-second commercial that first aired during the first quarter of Super Bowl LIII on Feb. 3. The ad depicts the purported Bud Light king, a knight and a wizard discussing how the Anheuser-Busch beer is brewed with just water, rice, hops and barley when a giant barrel of corn syrup is mistakenly delivered.
The group then embarks on a long and dangerous journey to deliver the barrel to the correct address. When they arrive at the Miller Lite castle, a man standing at the top says, "That's not our corn syrup, we received our shipment this morning. Try the Coors Light castle, they also use corn syrup."
Upon arriving at the Coors Light castle, a man at the top says, "Looks like the corn syrup has come home to be brewed."
The closing scene of the commercial is a tall, overflowing glass of Bud Light and the statement, "Brewed with no Corn Syrup."
MillerCoors owns Miller Lite and Coors Light.
"The commercial falsely claims that the corn syrup is going to be 'brewed.' It does not mention barley, hops, or even water as ingredients in Coors Light or Miller Lite," the complaint states.
The lawsuit also cites other similar ads that Anheuser-Busch has continued to air since the Super Bowl, as well as billboards promoting Bud Light that read, "100% less corn syrup than Coors Light" and "100% less corn syrup than Miller Lite."
"Not only does this imply that corn syrup is the only or primary ingredient in Miller Lite and Coors Light, but the advertisements also falsely imply that there is corn syrup present in the Coors Light and Miller Lite final products, rendering these beers inferior," the complaint states, noting that any corn syrup used in the fermentation process is consumed and broken down by the yeast.
"No corn syrup is in the glass, bottle or can of Miller Lite or Coors Lite that consumers drink," the complaint states.
Gemma Hart, vice president of communications for Anheuser-Busch, said in a statement that the Bud Light campaign "intended to point out a key difference from Miller Lite and Coors Light."
"Those beers are brewed with corn syrup; Bud Light is not. These are facts," Hart continued. "MillerCoors has admitted to using corn syrup on its website, in social media, in a full page ad thanking Bud Light following the Super Bowl, and even in the lawsuit itself."
But MillerCoors claims the Bud Light campaign contradicts the fact that Anheuser-Bush does use corn syrup as a fermentation aid in several of its beverages, including Stella Artois Cidre and Bon & Viv Spiked Seltzer. The St. Louis-based company also adds high-fructose corn syrup to several of its other products, according to the complaint.
MillerCoors is seeking an injunction to stop the ad campaign. The Chicago-based company is also demanding a trial by jury.
"We have always believed in transparency, which is why we were the first major brewer to put nutritional information and all of our ingredients online," MillerCoors said in a statement to ABC News on Thursday. "But while its Bud Light brand is talking all about transparency, Anheuser-Busch has admitted that its campaign was designed to mislead the public. Anheuser-Busch is fearmongering over a common beer ingredient it uses in many of its own beers, as a fermentation aid that is not even present in the final product. This deliberate deception is bad for the entire beer category. We are showing the world the truth."
Anheuser-Busch said it has "no plans" to pull the campaign.
"MillerCoors’ lawsuit is baseless and will not deter Bud Light from providing consumers with the transparency they demand," Hart said in the statement. "We stand behind the Bud Light transparency campaign and have no plans to change the advertising.”
ABC News' Kate Hodgson, Whitney Lloyd, David Reiter and Layne Winn contributed to this report.