Swedish authorities released the EU-sanctioned tanker Flora 1 after an investigation into a Baltic Sea oil spill found they did not have sufficient evidence to conclude that the vessel caused the leak, the Swedish Coast Guard said.
The spill was discovered Thursday, and the Flora 1 was boarded and detained on suspicion related to the incident, according to the Coast Guard. The Coast Guard said the spill stretched about 12 kilometers (8 miles) and that investigators had not found sufficient evidence that the tanker was at fault.
Investigators also said that when the ship was stopped Friday, its flag status was initially unclear. The Coast Guard said Cameroon later confirmed that the vessel was sailing under its flag.
Flora 1 has been on the European Union’s list of sanctioned vessels for carrying Russian oil and for “practicing irregular and high-risk shipping practices.” The EU sanctions, described in the Coast Guard account, are aimed at the “shadow fleet” that emerged after the Group of Seven imposed a price cap on Russian oil, a move designed to limit revenue flowing to Russia’s war in Ukraine.
The sanctions regime, as described by the Coast Guard, works by barring insurance and shipping companies from handling oil above the cap, pushing more shipments into the hands of fleets that are not bound by those restrictions. The Coast Guard said those tankers are often aging and operate with ownership and insurance based in countries that do not observe the price cap.
The Coast Guard account also pointed to safety concerns raised by the way some of these vessels operate, including risks of environmental harm and uncertainty over who would pay for cleanup. It said the Flora 1 had previously been owned by a Hong Kong company as of late 2025 and has been sanctioned by several other governments, while its name and flag status have changed multiple times.
The Coast Guard said investigators had also linked Flora 1 to behavior that can be used to conceal shipping activity, including observed turning off automatic tracking systems that transmit location information. It also referenced ship-to-ship transfers as a technique that can be used to disguise the origins of an oil cargo. Sanctions, the Coast Guard said, forbid transactions involving the named vessel.
As this investigation concludes without evidence of fault, the release highlights the gap between sanctions aimed at presumed Russia-linked shipping practices and the separate burden of proof required to determine responsibility for a specific environmental incident.