Various forum threads around the internet have appeared during the past few days claiming that certain map content in S.T.A.L.K.E.R. appears to be taken from Doom 3 and Half-Life 2.
At this time it is not known whether the content was authorized for GSC Game World, but the forums and id Software's CEO seem to think that the files were used without permission.
Shacknews has the response from Todd Hollshead, CEO of id:
"I've seen a post on a web forum that claims DOOM3 assets are used in another game, but we've been working hard on Enemy Territory: Quake Wars as well as our own internal project and have not had the time to fully investigate or otherwise verify that the claim is true. Only from what I've seen on the Web, it's concerning. However, it may turn out to be nothing. Nevertheless, it would be improper to make any decision about a course of action until we find out whether the claim is true, and what assets from DOOM3, if any, have potentially been used."
Specifically, the names and images in S.T.A.L.K.E.R.'s "lights" directory seem to be similar, if not the same in a few cases.
Sources:
Doom3World,
Mapcore,
Shacknews