If you're spending the weekend on the sunny holiday island of Bornholm and fancy a cold swim, you might want to go somewhere other than Balka Strand.

The popular beach, which is south of Nexø, will remain closed for the next couple of days after human faeces were found scattered on a large stretch of its famous white sand.

"We have had a spill of human excrement," Michael Mortensen, a spokesperson for Bornholm Police, told Børsen.

"At around 5pm we discovered that roughly 200 metres of the beach was polluted with human waste."

Ship spilled sewage
A passing ship is suspected of being the source of the excrement.

"We can't see how there could be any defect in our sewage system, so we assume that it came from a ship that unloaded its septic tank into the water and it somehow ended up on the beach," Mortensen said.

Workers began on Wednesday to clean up Balka Strand, but police couldn't say when the beach will be opened to the public again.