In a previous statement, police said they were searching for a teenager, but Örebro police spokesman Mats Nylén told Swedish Radio that they have changed their minds.
Investigators are now pursuing new leads indicating the involvement of an adult man who has tried to cover his tracks and to derail the investigation.
The police believe that the girl could have been in touch with the man on the internet.
Police have received two reports connected to the case and several indications that there could be one or several other victims involved. More suspects may surface, too. However, so far there is no named criminal suspect in the case.
Earlier, the Swedish School Inspectorate held an emergency meeting over the situation at the girl's school.
Many suspected that bullying, including abuse via the internet was a cause of the teenager's suicide, and several reports to the School Inspectorate claimed the school is part of the problem.
Newspaper Svenska Dagbladet reported that the Inspectorate is not pleased that the girl's school did not take any concrete steps to deal with bullying.
In Kumla, support is on offer at the Kvisten youth centre, with counsellors, social workers and psychologists on hand.The municipality has said that anyone who needs to talk is welcome to visit.