League of Legends developer Riot Games is working on an unannounced fighting game, according to Evo fighting game tournament co-founder Tom Cannon, who also works at Riot. Cannon confirmed the development during an interview at Evo, as spotted by esports reporter Rod “Slasher” Breslau.

“Back in 2016, when we joined forces with Riot, I said that we were going to go in the hole for a while,” Cannon said, “and I want to be able to let people in on maybe the worst kept secret in the universe, which is I can confirm that we are working on a fighting game for Riot.”

Riot Games acquired Cannon’s former studio, Radiant Entertainment, which he founded with his brother Tony Cannon, in 2016. Radiant was working on a PC fighting game at the time called Rising Thunder, which featured giant robots battling in one-on-one fights, and pursued a simplified approach to the complicated move inputs seen in other fighting games.

While Riot’s work on a fighting game has been heavily rumored, the developer has not officially announced a new project or given any indication about the former Radiant Entertainment team’s work at the studio.

The Evo fighting game championship is happening this weekend, Aug. 2-4, in Las Vegas.