Woolworths, Game and Maplin have been slammed by Which Computing magazine and Trading Standards for selling 18-rated video games to a 15-year-old.

During an undercover investigation by Which, Woolworths sold Grand Theft Auto (GTA) – Vice City Stories, which shows scenes of sex and violence, while specialist shop Game sold Condemned 2, which is subtitled 'a terrifying descent into chaos', to the girl.

Meanwhile, in the Maplin store, the shop assistant asked the investigator's age, but didn't refuse the sale of the 18-rated Hitman, even though she admitted she was 15.

"It's shocking and surprising that 18-rated games have been sold to a child as young as 15 by household names," said Sarah Kidner, editor of Which Computing. "The jury's still out on whether violent video games have a negative influence on behaviour but, whatever your view, it's still illegal to sell 18-rated games to minors."

Retailers face a maximum £5,000 penalty and/or six months in jail for selling games to those who have not reached the age specified in the British Board of Film Classification (BBFC) certificate. Woolworths, Game and Maplin told Which Computing they were looking in to the incidents.

"Staff should realise that they have a moral and legal duty to stop these sales from taking place," said Ash Shah, assistant head of Brent and Harrow Council trading standards.

"There is a mixed but growing body of evidence that very violent games like this can sometimes influence under-age players with reports of anti social behaviour linked to them, in extreme cases even fatalities."