An oil spill arising from the elderly “shadow” fleet of tankers carrying Russian, Iranian and Venezuelan oil could provide a sharp boost to mainstream tanker rates.

This is according to French shipbroker BRS Group, which argues that any such environmental disaster would increase scrutiny on this big rogue sub-sector of the market.

“In the case of an accident occurring leading to pollution from a shadow tanker, we believe that the use of vintage tonnage to carry Iranian, Venezuelan and Russian barrels would come into focus,” the Paris shop said.