A Panamanian-registered freighter sailing from Russia was detained early on Sunday on suspicion of flushing coal residue into the sea off Sweden’s southern coast, the Swedish coastguard reported.
Coastguard officials acting on instruction from prosecutors had boarded the Hui Yuan off the port of Ystad, the agency said.
On overflying the Baltic Sea on Saturday, a coastguard plane had noticed that the bulk carrier was discharging coal residue into the water, the report said.
“This is a violation of the Environment Code,” it said.
A preliminary investigation has been launched, according to the coastguard, which said that the 225-metre freighter was bound for Las Palmas in Spain.
Sweden’s TT news agency reported that the coastguard had now boarded four vessels since last month, two of them off the south coast.
On April 3, the coastguard searched a tanker thought to be part of the shadow fleet that Moscow uses to evade Western sanctions on Russian oil exports imposed during the course of the Ukraine war.
The tankers are believed to pose a serious environmental risk.