“It concerns crimes which were committed against several children on different occasions. The crimes took place in Jönköping,” prosecutor Anna Mårtensson said in a statement on Wednesday morning.
The teacher, a man in his forties, is suspected of having abused four children at the school, which has pupils between one and five years old.
The crimes were first reported on October 20th and the man was arrested three days later.
He has since had three remand hearings, the latest of which was held on Tuesday, to keep him in custody while prosecutors pursued their investigation.
A spokesperson for the organization behind the preschool told the Jönköpingsnytt news website that he is distraught over the allegations against the man, who was immediately suspended from his job when the suspicions of alleged abuse came to light.
The man has been active in the organization for which he worked.
All parents of children at the school have been informed, and both they and personnel at the school have been offered counselling support to deal with the situation.
During the investigation, new suspicions have come to light, including child pornography.
Prosecutors are expected to hold a press conference on the case later on Wednesday.