A website criticised for encouraging young girls to embrace plastic surgery and dieting is being investigated by a communications watchdog over claims that it has breached rules about targeting children with premium rate phone lines. PhonepayPlus is examining claims that the Miss Bimbo game exploits children's naivety and contains content that parents would feel unsuitable for children.

The organisation, formerly called Icstis and which regulates premium rate phone services, said the investigation was launched after the site was rounded on for sending a dangerous message about dieting. Parents and healthcare professionals working with those suffering bulimia and anorexia condemned the site as "lethal".

Miss Bimbo, described by its creators as a fashion game, has attracted prepubescent children as young as 9. It invites children to create a virtual doll, monitor its diet and weight and buy it breast implants and facelifts.

Children sign up free of charge and automatically receive 1,000 "dollars" to buy treatments and clothes. They are also invited to buy extra dollars by sending £1.50 text messages to afford "gifts" for the character.

If the Miss Bimbo service is found to have flouted guidelines it faces a fine of up to £250,000 and possible ban from providing premium rate phones services.

A PhonepayPlus spokesman said: "Our code of practice has specific requirements for services that are targeted at children or likely to be particularly attractive to children. In addition to issues around cost, our rules make clear that services should not exploit or provide content that parents are likely to think unacceptable. We are looking into claims that the Miss Bimbo service might contravene these requirements."

Chris Evans, the British businessman helping to introduce Miss Bimbo to Britain, insisted that the game could be completed without using the premium rate number to buy extra "dollars". He said the designers had decided to remove virtual diet pills from the game following the public outcry about the message it sent to girls.