The makers of Grand Theft Auto: San Andreas have stopped manufacturing the current version of the title after pornographic games were found hidden in the code. 

Rockstar Games and Take-Two Interactive are now working on a new version of the title, in which the player can steal cars, shoot characters and deal drugs, without any pornographic content. 

The Entertainment Software Rating Board (ESRB) has changed the rating of Grand Theft Auto: San Andreas on all platforms from 'Mature 17+ (M)' to 'Adults Only 18+'.

"Take-Two and Rockstar have always worked to keep mature-themed video game content out of the hands of children and we will continue to work closely with the ESRB and community leaders to improve and better promote a reliable rating system to help consumers make informed choices about which video games are appropriate for each individual," said Paul Eibeler, Take-Two's president and chief executive.

"Rockstar Games is pleased that the investigation is now settled and looks forward to returning its focus on making innovative and groundbreaking video games for a mature audience."

The unauthorised code can only be accessed using a third-party program called Hot Coffee, designed by Patrick Wildenborg. Rockstar will shortly be releasing a patch that prevents the modification from working. 

The modification, which has been tested by Gamespot, accesses a soft porn mission within the game where the player has to arouse his girlfriend with a steady rhythm with the controller to build up an onscreen 'excitement meter'.

If the meter drops to 'Empty' the game admonishes the player with the warning: 'Failure to satisfy a woman is a crime!'. Filling the meter leads the female character to tell the player that he is 'the man'. 

"The nude models that are used as a bonus in the quick action version of the mod were also present on the original disk. But all this material is completely inaccessible in an unmodded version of the game," said Wildenborg.

"It cannot therefore be considered a cheat, Easter-egg or hidden feature, but is most probably just leftover material from a gameplay idea that didn't make the final release."

The hidden game has caused a furore in the US, with religious leaders and heavyweights like Hillary Clinton calling for it to be withdrawn.