Recently, an early build of Grand Theft Auto IV fell into the hands of dataminers. They found specific materials related to zombie content.
Animations, as well as icons for pickups and weapons, remained in the files. The community speculated that the developers had cut out a zombie mini-game.
Some fans began asking Obbe Vermeij, former technical director of Rockstar North, about the "zombie mode."
He explained that these were simply remnants of artists' experiments – at the time, they were trying to insert zombies everywhere:
I don't recall there being zombies in [Grand Theft Auto IV]. The artists were always trying to put zombies somewhere, but it never got far.