Police in Mariehamn, Åland have suspended an investigation into a suspected incident of vandalism at the Russian consulate this spring, Radio Åland has reported.
The incident occurred on the night before May Day, prompting Russia to contact the Finnish foreign ministry with concerns about an "explosive noise device" and other objects thrown onto the consulate's territory.
Police said investigators have not identified or found possible suspects and that fingerprint and DNA samples taken at the scene did not reveal any matches.
Investigators also found that the image quality of security camera video footage was so poor that it made it impossible to identify the people in it.
Åland police said that the case will be revisited if more information emerges.