Half-Life 3 has appeared in a list of products set to be exhibited at Gamescom in Cologne this week.
The official Gamescom website points to a PDF file containing a "list of all the new hardware and software products" set to appear in Germany.
[UPDATE: Valve has told CVG: "We are not showing any games in Cologne this year."]
The list also contains Dragon Age 3 from EA, although given its disclaimer that Gamescom takes "no responsibility for the correctness of this information", it's unclear how accurate its contents should be considered.
Valve is set to have a presence at the German convention - which officially kicks off tomorrow - though CVG understands this is restrained to just private meetings.
Earlier this year supposed Half-Life 3 concept art appeared online, showing key character Alyx Vance in a winter setting.
We strongly suspect the Gamescom website might call 'error' on this one, but we've contacted Valve for comment just in case.