Anheuser-Busch is accusing arch-rival MillerCoors of stealing the recipe for its most popular product, the latest escalation of a legal fight that began over a commercial that ran during this year’s Super Bowl.
In a court filing Thursday, the maker of Bud Light claims MillerCoors received the recipe via one of its employees, a former A-B employee who was in communication with current Anheuser-Busch workers that violated confidentiality agreements.
All of this ties back to the ad campaign Bud Light ran during the Super Bowl that mocked MillerCoors use of corn syrup in its brewing and claimed A-B products had “no corn syrup.”
“Corngate,” as it became known, seemed to be the usual WWE-theatrics of two industry giants at the beginning, but in March MillerCoors filed suit against Anheuser-Busch, seeking (and eventually receiving) injunctive relief for what it called “a false and misleading advertising campaign targeting Miller Lite and Coors Light.”
As part of that ongoing case, MillerCoors allegedly produced documents showing the recipes for Bud Light and Michelob Ultra, A-B’s best selling beer and fastest rising brand, respectively. The suit alleges that MillerCoors senior management prompted the messages between the former A-B employee and current workers.
“We will enforce our right to uncover how high up this may reach in the MillerCoors organization,” said Anheuser-Busch in a statement. “We take our trade secrets seriously and will protect them to the fullest extent of the law.”
MillerCoors, in a statement to Fortune, denied the charges and said Anheuser-Busch was simply trying to muddy the waters.
“Anheuser Busch has lost three major federal rulings in this case and now they are simply trying to distract from the basic fact that they intentionally misled American consumers,” said Adam Collins, VP of communication for MillerCoors in the U.S. “MillerCoors respects confidential information and takes any contrary allegations seriously, but if the ingredients are a secret, why did they spend tens of millions of dollars telling the entire world what’s in Bud Light? And why are the ingredients printed on Bud Light’s packaging in giant letters?”
More must-read stories from Fortune:
—Beer City: These women are at the forefront of Asheville’s explosive fermentation industry
—Michelob was really early to this whole marketing ‘beer as wellness’ trend
—Behind the scenes at the largest beer competition in the world
—Why this award-winning champagne maker is turning to sake
—Dom Pérignon looks beyond producing the next vintage and adjusts to the climate crisis
Follow Fortune on Flipboard to stay up-to-date on the latest news and analysis.