Gamescom organisers have denied internet scuttlebutt that claimed Rockstar would showcase Grand Theft Auto 5 at the German event.
Unknown projects from Valve and a new Rockstar Table Tennis Tournament title were also listed for the show this year.
The details appeared on a LinkedIn profile for Gamescom employee Gerald Bauser, who claims to be involved with managing this year's event.
But Gamescom's organisers have told Eurogamer they "don't know" Bauser.
"He is not working for the official organisers of Gamescom (Koelnmesse and BIU)", a spokesman said.
Bauser's profile also lists known titles such as Assassin's Creed 3, Call of Duty: Black Ops 2 and "World of Warcraft expansion" (presumably Mists of Pandaria), alongside an erroneously-numbered listing for "Guild Wars 3" on PC and consoles.
An official Gamescom 2012 showreel posted online last week included a clip from the initial Grand Theft Auto 5 trailer, prompting speculation that Rockstar would reveal more about the game at the event.