The UK has raised the threat of jail and large fines if shipbrokers fail to stop sanctions-busting sales deals for tankers that end up in the Russian trade.

The government’s trade ministry listed 19 potential red flags that brokers should look out for that would suggest secondhand tankers are likely to end up hauling Russian crude and products.

The UK introduced rules in March 2022 limiting the sale or broking of tankers for the Russian market but a brisk secondhand trade has continued in elderly vessels destined for the shadow fleet.