German police are looking for what they presume to be a "repentant offender" who is believed to have stolen goldfish from a garden pond in the Bavarian town of Waldkraiburg, some 70 kilometers (43 miles) east of Munich.
The apparent theft was reported by the owner on Friday. On Monday, however, the owner contacted the police once again to tell them that all 80 fish were back in their pond. The fish were apparently not harmed.
"It is still a mystery who returned them," the police said in a statement.
Police officers told DW that was still no indication on the identity of the perpetrators or the possible motive behind the incident.
The 42-year-old owner estimated his fish to be worth around €250 ($275), according to a report in the Süddeutsche Zeitung. He had discovered the disappearance after being away from home for several days last week.
Despite the fish being returned to the pond, police are continuing the investigation and have urged public to come forward with any information on the perpetrator. If discovered, the suspect could face charges of theft and disturbance of peace.