UK ship manager V.Group has ceased to handle 30 tankers after they moved into the shadow fleet trading in Russian, Iran and Venezuelan oil.

Chief executive Rene Kofod-Olsen told Reuters that the ships had been sold to companies that did not pass its compliance checks.

He said the tankers had been “lost … to the dark fleet”.

“Typically, we will try and retain management of a new owner. Clearly, that was not possible for us,” the CEO added.

V.Group handles nearly 300 tankers out of a pool of more than 3,500 managed vessels.

Kofod-Olsen also said the group has been approached by owners of other ships that did not meet compliance standards.

He noted that purchases of these tankers for sanctioned trades had tailed off in recent months.

But he warned: “These assets are ageing, the risk is just going to go up. They are sailing full of fossil fuels or molecules, and they are a sailing danger.”

TradeWinds reported earlier on Monday that Finland has asked the European Union to “procure” a vessel to be ready to deal with any oil spills from the Russian-trading tanker fleet in the northern Baltic Sea.

The Finnish Ministry of Transport & Communications said carriage of Russian exports on often elderly vessels is a growing threat to the region.

Harsh winter conditions will increase the risks, as these tankers may be “poorly equipped and not suited for icy conditions”, it added.

In May, the Guardian reported that the UK and Finland were discussing plans to require third parties to do more to block the Russian-trading fleet operating in the Baltic and the English Channel.