US politicians have stepped into the storm over secret sex scenes in the best-selling Grand Theft Auto: San Andreas game.
The GTA series is one of the world's most popular games
The House of Representatives has overwhelmingly called for investigation into the companies behind the game.
The uproar is over explicit sexual scenes in the game that can be unlocked with software created by a fan.
Last week the game was given an adults-only rating, leading big US stores to stop selling the title.
GTA: San Andreas was originally released in October in the US with an M for mature rating, meaning it was suitable for players 17 and older.
But the industry group responsible for ratings, the Entertainment Software Ratings Board, changed it to an adults-only rating after a fan of the game found a way to access graphic sexual scenes.
The rating change led to shops such as Wal-Mart, Target, Circuit City and Best Buy removing the game from their shelves.
The stores have a policy of not stocking titles with an adults-only rating.
GTA's publisher, Take Two, initially denied the scenes were part of the game but later admitted the scenes were contained in the retail version of San Andreas.
'Profit from deceit'
The controversy reached the halls of Congress on Monday.
The House of Representatives voting 355 to 21 for a federal investigation to determine if the companies behind San Andreas intentionally deceived the industry's ratings board.
"The release of Grand Theft Auto: San Andreas was widely anticipated, but an adults-only rating would have severely limited its sales in retail outlets," said Congressman Fred Upton of Michigan.
GTA kickstarted the shooting and driving genre of games
"It appears that the publisher has blatantly circumvented the rules in order to peddle sexually explicit material to our youth, and they should be held accountable. A company cannot be allowed to profit from deceit."
The vote follows calls by US senator Hillary Clinton for an investigation into who put the sex scenes into San Andreas.
Rockstar Games has stopped producing the current version of the game and is working on a version that will qualify for the M rating.
GTA: San Andreas was one of the best-selling games of 2004. The title already has an 18 age rating in the UK.
The GTA series of games has created controversy in the past. Previous versions have been criticised by parent groups and lawmakers for their depictions of violence and sex.