More than 90 videos and images from the next edition of the Grant Theft Auto franchise have been leaked online by a hacker, the game's developers say.

Axar.az reports that the leaked content was posted on Sunday after what is being described as one of gaming's biggest security breaches.

Rockstar Games said it remained unclear how the "network intrusion" occurred, but confirmed "early development footage" from GTA VI had been stolen.

The footage was put on the GTAForums site by a user called teapotuberhacker.

The hacker claimed to have gained access to the data by breaching Rockstar's internal feed on the Slack messaging app, and invited executives to negotiate to avoid further leaks.

Additional revelations could include source code, assets, and testing builds from both GTA 5 and GTA 6, which could be damaging to the company's operations.