German authorities are trying to uncover the identity of a person who's offering child pornography in the virtual world of ''Second Life.''

A German, whose avatar—or online character—is a 13-year-old girl, has been offering to provide real photos that contain child pornography to other denizens of the online service, prosecutor Peter Vogt said Thursday.

Authorities hope to uncover the person's identity within days with help from San Francisco-based Linden Lab, which runs the online universe where people make virtual friends, listen to concerts, shop and even campaign for political office.

''Linden Lab has been working very hard here against this abuser who misuses this game as a platform for child porn,'' said Vogt, who heads Germany's Central Agency for the Prevention of Child Pornography.

Oliver Habel, the Munich attorney who represents Linden Lab in Germany, said the company is cooperating fully with the police.

''It is the very clear policy of Linden Lab that something like this cannot be tolerated,'' he said.

The misuse of ''Second Life'' by purveyors of child pornography came to Vogt's attention after German broadcaster ARD's ''Report Mainz'' aired a report this week highlighting the problem.

Besides the offer of real child porn, ARD also documented that online characters depicting children were being virtually abused. Child pornography using computer-generated images is illegal in Germany, punishable from between three months to five years in jail.

In its blog, Linden Lab said Wednesday it had identified a 54-year-old man and a 27-year-old woman as the owners of the avatars in question.

''Both were immediately banned from Second Life,'' the company wrote on the blog. It gave no further details.

In the case of the distribution of real child pornography, Vogt said it is almost certain there are more people out there using the game for similar purposes, and that Linden Lab was working on ways to crack down.

''Linden Lab is very agreeable to help me contain these criminal activities,'' he said. ''One can probably never totally stop them though, just like one cannot totally stop the other criminal uses of the Internet.''

Second Life is a virtual world in which players—called ''residents''—interact with each other through their avatars. They can do basically anything that people can in real life, including buying and selling property, participating in group or individual activities, or socializing.

There are more than 6 million registered participants and many real opportunities in the virtual world. Companies have rushed to place ads for virtual and real-life products, musicians like Duran Duran and Suzanne Vega have broadcast virtual concerts there, and Democratic presidential hopeful John Edwards even has a campaign headquarters set up there.