Chipotle made waves earlier this year when the chain completely banned genetically modified ingredients from its menu. But now, a new lawsuit claims that might not actually be the case. 

The law firm Kaplan Fox & Kilsheimer filed a federal class action lawsuit this week against Chipotle, on behalf of all customers who bought food between April 27 and today. The suit claims that Chipotle has been "misleading" customers, since some menu items still contain GMOs. For example, its meat and dairy allegedly comes from animals that eat feed containing GMOs, and its soft drinks still contain corn syrup, which is a genetically modified ingredient. 

According to Reuters, plaintiff Colleen Gallagher seeks unspecified damages in the suit. "As Chipotle told consumers it was 'G-M-Over it,' the opposite was true," she said. "In fact, Chipotle's menu as never been at any time free of GMOs." 

Chris Arnold, Chipotle's communications director, told Fortune that the lawsuit was "meritless" and "filled with inaccuracies." "Chipotle has always been honest and transparent with its customers, and the messaging surrounding our use of non-GMO ingredients is no exception," he said. And he says it's clear that the meat they serve is from animals which eat GMO grains, "that does not mean that our meat is GMO, any more than people would be genetically modified if they ate GMO grains." And beverages don't count as "food," he said, meaning their advertising still holds water.

Chipotle's website does trumpet its lack of GMOs, but its specific page on the topic does address the meat, dairy, and soda issues. "We are working hard on this challenge, and have made substantial progress," the website reads. "For example, the 100% grass-fed beef served in many Chipotle restaurants was not fed GMO grain—or any grain, for that matter."