The science fiction reality
Sex, violence and video games
An increasing number of video games now contain sex as well as violence and swearing, the British Board of Film Classification (BBFC) said.
Games with sexual elements, like Grand Theft Auto - in which players can buy virtual prostitutes - are on the rise, the regulator said.
"On the whole sexual activity in games is nowhere near as common as violence, but it is becoming more common," said spokeswoman Sue Clark.
Her comments came as new research revealed that almost three quarters (74%) of parents were concerned about the content of some video games.
An even greater number of parents (79%) believed video games may affect the behaviour of some children, according to a YouGov poll for the BBFC.
In addition to sex and violence in games, bad language was also an issue, Ms Clark added.
In September 2007, Prime Minister Gordon Brown asked Dr Tanya Byron to lead an independent review into child safety online and in video games. The review suggested a hybrid classification system in which BBFC logos appear on the front of all games while Pan European Game Information, the gaming industry's own regulator, continues to rate all 3+ and 7+ games.
The BBFC's survey found that 74% of parents believed video games should be regulated by an independent regulator.
More than three quarters (77%) believed video game ratings should reflect the concerns of UK parents and 82% believe it would help them if video games used the same ratings as films and DVDs.
The UK Council for Child Internet Safety is considering Ms Byron's proposals.