US retailers are rumoured to be selling copies of Halo Reach early in response to its appearance on torrent sites.
Speculation of under-the-counter sales emerged after a photograph of what appears to be a legitimate customer copy appeared on JustPushStart.
It is thought that the photo may depict a promotional edition of the game, although this was not indicated on the box.
Microsoft is yet to confirm whether it will bring the title’s release forward to combat piracy, but it did state that users caught playing an illegitimate version could face an Xbox Live ban.
Halo Reach will be released worldwide on September 14.