Paris - It seemed like an open-and-shut case - a beach mystery that a 10-year-old detective with an ice cream and some time on his hands could figure out.
For the better part of a decade, hundreds of harbour porpoises washed up along the southeast coastline of the North Sea coastline.
Their lifeless bodies were gashed with horrible injuries. The slash marks pointed to a pretty obvious perpetrator - some apex predator of the sea or maybe a ship's propellor.
Instead, many of the slayings should be laid at the flippered feet of the innocent-eyed grey seal, says a team of detective biologists in the Netherlands.
DNA found in bite wounds implicate grey seals in the massacre... suggesting the mammals may also pose a risk to humans, the researchers said.