Nudity in the videogame "Halo 2" for Windows Vista has pushed back the long-awaited title's official release to the end of the month, Microsoft said Friday.

Microsoft has already released an optional patch to remove the problematic content.

Originally scheduled to ship on Tuesday, May 22, Halo 2 has been delayed to the 31st so retailers can slap stickers on already-in-hand copies. "It has come to our attention that an unfortunate, obscure content error which includes partial nudity was included in our initial production of Halo 2 for Windows Vista," a company spokesman said.

"As such, we have updated the initial game packaging at retailers with a label, so customers are aware before purchasing the game. This packaging will only be labelled for the initial run of games; subsequent shipments will not include the content."

From messages posted on Microsoft's own Halo 2 support forums, however, copies of the nudity-afflicted game have made it into customers' hands. "Just drove to circuit city and bought a copy," a user identified as akakia said Wednesday on the forum. Best Buy, however, has not yet put Halo 2 on shelves, reported several users on the same thread. A quick check of the two chain's Web sites confirmed that Circuit City has Halo 2 in stock, but that Best Buy reported it as available for pre-order only.

A 2MB update was posted on the Halo 2 site Tuesday. The update, said the Microsoft spokesman, "removes the content error" and thus the nudity. "It's optional," he added. Subsequent production runs of the game will have the nudity removed.

"It was added in jest, and not meant to be in the final build," the spokesman said of the nude code.

The incident is reminiscent of the 2005 brouhaha over Take Two's "Grand Theft Auto: San Andreas" videogame and a "mod," or modification dubbed "Hot Coffee" that unlocked graphic sex scenes buried in the game's code. That disclosure led to an industry rating board changing the game's rating from "M" (Mature 17+) to "AO" (Adults Only 18+) and lawmakers, including Senator Hillary Clinton, calling for an investigation.

Halo 2 currently carries an M rating.