The three-year-old girl told what had happened when her guardian picked her up from preschool. The man initially denied the allegations but has since confessed.
He has been detained since October 3.
Prosecutor Fredrik Beijar believes that the crime is serious considering the girl's age, but also means that the man exploited his position as an employee at the preschool.
"The crime has also taken place at a location where the girl was left in his care and had the right to feel safe," says Fredrik Beijar in a press release.
The police have received new reports - "nearly ten" - against the man for suspected sexual offenses. These come primarily from parents with children at the same preschool. In several cases, the suspicions have not been concrete enough for investigation, and in others, the evidence has not been sufficient for prosecution. Only one of these investigations is still ongoing.