The previous impression given was the man had "only" tricked boys into touching his genitals, but police now confirm that the man is a dangerous sex criminal, newspaper Dagbladet reports.

"Out of consideration to the many victims I do not wish to go into detail publicly about the Pocket Man's assaults. He is a dangerous sexual serial criminal. I can confirm that the offenses are comparable to rape," Follo police chief Arne Jørgen Olafsen told Dagbladet.

Olafsen also believes that there could be significant unreported cases above the over 120 they know of.

Internally, police consider the investigation a scandal, with only those directly involved knowing how serious the assaults have been. Olafsen said many have envisaged the Pocket Man as a pathetic flasher.

"Unfortunately many police and others have not understood how serious this case is. The attacks have been monstrous sexual assaults," Olafsen said.

Now police say they will mobilize all necessary resources to arrest the man whose nickname comes from his ploy of charming young boys and then asking them to help him find something in his pocket. The man reportedly 'thanks' the children afterwards with rewards of money.

Police have DNA evidence from four of the assaults and forensic tests conclude that they were carried out by one man. This breakthrough led to a public offensive that secured many tips from the public last year, and police released details, a sketch, security video footage of the suspect and other information on a dedicated web site.

"We have no news about the Pocket Man since the case became well known last summer. His method of operation shows that he is a typical serial criminal who will not stop until he is caught," said superintendent Håvard Aksnes at the National Criminal Investigation Service (NCIS).

Aksnes said that the descriptions indicate a man in his 40s, often with bandaged arms when he contacts children, and that the young boys find him kind and reassuring.

Aksnes urged the public to contact police if they had anything to contribute to the investigation.