Microsoft has promised to take "vigorous action" against those who pirate Gears of War: Judgment after a leaked version surfaced yesterday, a month before its official release date.

Copies of the Gears of War prequel are up on torrent sites, and Microsoft is threatening lifetime Xbox Live console bans for those detected playing it.

"We are aware of isolated cases in which Gears of War: Judgment content has been propped on the web and are working closely with our security teams and law enforcement to address the situation immediately," a Microsoft spokesperson told Eurogamer.

"Playing pirated copies of games, such as Gears of War: Judgment, is a violation of the Xbox Live Terms of Use and will result in enforcement action, such as account and console bans."

Gears of War: Judgment is being developed by Epic Games subsidiary and Bulletstorm studio People Can Fly.

It is due out for Xbox 360 on March 19.