Today, one of the most popular recent game industry rumors showed signs of turning into a very real scandal.

Following a verbal lashing this week from California Assemblyman Leland Yee (D-San Francisco), the Entertainment Software Ratings Board (ESRB) today said it was launching an investigation into Rockstar Games' best-seller Grand Theft Auto: San Andreas to determine whether the game contained sexually explicit minigames hidden in its code.

ESRB president Patricia Vance said her organization has "opened an investigation into the circumstances surrounding the 'Hot Coffee' modification." "Hot Coffee" refers to the mod that, when installed on a PC with San Andreas on it, unlocks several minigames that prompt players to have the game's hero engage in X-rated acts.

The ESRB's investigation will examine whether the mod unlocks preexisting code, as appears to be the case, or is actually a purely third-party creation. Its ultimate purpose will be to determine if Take-Two violated ESRB regulations requiring "full disclosure of pertinent content."

"The integrity of the ESRB rating system is founded on the trust of consumers who increasingly depend on it to provide complete and accurate information about what's in a game. If after a thorough and objective investigation of all the relevant facts surrounding this modification, we determine a violation of our rules has occurred, we will take appropriate action," Vance said in a statement released this morning.

Vance also had some choice words for Assemblyman Yee, who, in the same statement accusing the board of "failing to appropriately rate" Grand Theft Auto: San Andreas, also accused it of a "conflict of interest in rating games."

Yee implies the nonprofit ratings board, which was established in 1994 by the Entertainment Software Association (ESA), shies away from AO ratings, regardless of the content. Most major retailers refuse to sell AO-rated games, thereby denying such titles broad distribution.

"Assemblyman Yee has been on a crusade for years to undermine the integrity of the ESRB, and in so doing, generate support for his legislative agenda. His latest attempt to win political points is to claim, without any legitimate basis, that a game rated for ages 17 and older, with explicit content descriptors prominently displayed on every box, has been inappropriately rated," Vance said.

Stating the agenda of the board was above reproach and that contrary to Yee's comments that the ESRB has "failed our parents" with San Andreas' M rating, Vance claimed "research shows parents overwhelmingly find ESRB ratings to be effective."

"We will do whatever it takes to maintain their confidence in them and the integrity of the system," Vance concluded.

[UPDATE] Rockstar alerted the press late in the day that it is aware of the investigation by the ESRB. "We can confirm the ESRB is conducting an investigation and that we will be complying fully with their enquiries," the statement read. "We thoroughly support the work of the ESRB, and believe that it has an exemplary record of rating games and promoting understanding of video game content. We also feel confident that the investigation will uphold the original rating of the game, as the work of the mod community is beyond the scope of either publishers or the ESRB."

This afternoon, when asked if the "Hot Coffee" code was included in game discs manufactured by Rockstar or its agents, the company commented more fully than it had previously. Specifically, a spokesperson for Rockstar told GameSpot News it was not.