Rockstar Games on Monday confirmed that videos and images from Grand Theft Auto VI had leaked online over the weekend in one of the biggest data breaches to hit the gaming industry. More than 90 files from the hotly anticipated game—the successor to 2013’s Grand Theft Auto V, one of the best-selling video games in history—were published on fan site GTAForums. A user with the handle “teapotuberhacker” shared the images and claimed to have obtained them by hacking Rockstar’s Slack feed and getting into the company’s servers. Rockstar Games’ parent company, Take-Two Interactive, has issued takedowns to scrub the leaked files from YouTube and Twitter, but they’ve already been shared widely online. The hacker has also threatened to leak the source code for Grand Theft Auto V, as well as the in-development version of Grand Theft Auto VI, asking Rockstar to negotiate a deal to prevent further leaks. “We recently suffered a network intrusion in which an unauthorized third party illegally accessed and downloaded confidential information from our systems, including early development footage for the next Grand Theft Auto,” Rockstar said in a statement shared on social media on Monday. “We are extremely disappointed to have any details of our next game shared with you all in this way,” the company added.