A group of American teenagers was instrumental in the capture of a suspected child molester following a classic internet sting.

The group set up an online persona at myspace.com, a social networking site popular with youngsters. The teenagers said this was done to cheer up a friend, who had recently been dumped by his girlfriend.

However, the group soon found that the fictitious 'Jessica' was getting increasingly sexual messages from a much older poster on the site.

They set up another identity and, when the same man contacted the new persona, they decided to string him along a little more.

The man sent the 'girl' a picture of himself and arranged to meet her in a nearby public park. When the teenagers recognised him from his photo they called the police, who swooped.

"Michael Ramos, 48, was charged with one felony count of attempting to commit a lewd act on a 15 year-old and two misdemeanour counts of attempted child molestation," Karen Martinez, a San Bernardino County deputy district attorney, told AP News.

Martinez explained that to face charges a person must "take a step toward completing that crime ... such as appearing in the place that was arranged upon. It is not just talking about it, thinking about it or wishing about it."