Worried relatives notified the Skärholmen police in southern Stockholm after they hadn't seen a family member for four days. Officers headed to the person's home immediately.
On arrival, they heard moaning coming from inside the locked bathroom and they broke down the door, the police wrote on their official Facebook page on Sunday.
Inside they found the missing person who had been locked in the bathroom when the door handle had broken.
The person was taken to hospital.
"I don't dare think what would have happened if there wasn't water in the temporary prison," the police wrote on Facebook.