The City of Oulu has filed a criminal complaint with police over repeated defecation in the water at the Linnanmaa swimming pool. The criminal complaint was first reported by the local daily, Kaleva.

Erkko Korpela, who manages the city’s swimming pools, confirmed the filing to Yle. He said there is a strong suspicion that these incidents have been the result of intentional actions, and not accidental.

"Children’s accidents have been ruled out. That has happened in the past. This clearly involves an adult," he told Yle.

Human excrement has been found in the swimming pool six times since the beginning of July, and the main pool has had to be closed five times. The facility only opened earlier this year.

Similar incidents in 2018 unresolved

City officials have decided to step up supervision of the swimming pool in northern Oulu as they attempt to identify the serial pooper.

For example, Korpela said that one additional swimming lifeguard will be added to the pool per shift. In addition, extra staff will be needed to check the swimming pool's CCTV footage.

"That is an activity covered by the Personal Data Protection Act, so not just anyone can watch those recordings," Korpela pointed out.

He added the incidents have caused a lot of extra work, planning and recruitment for the city’s sports services division, as well as financial losses.

"Surely some customers will vote with their feet and go elsewhere. We have received worried, surprised and even angry comments from customers," he said.

There was also a series of incidents in Oulu in 2018, where poop was found several times in a row in the Raksila swimming pool in the centre of the city, which has now been nearly demolished. At the time, officials decided that this was done as a malicious prank. A suspect was identified but not apprehended.