The boy was found dead on the facility's premises on Thursday morning.
"Our thoughts go out to the boy's relatives at this time," the Swedish State Institutions Board (SiS) writes in a press release.
The prosecutor suspects that a crime was involved in the death.
"The case was assigned to me today and there is a suspicion of a crime. I cannot say more at this time," prosecutor Lindha Strömberg tells SVT.
The incident will be investigated to establish the course of events, but SiS is not releasing any further information at this time.
