Tanker owners have pulled back from the Middle East Gulf in the past month amid growing tension in the world’s prime oil shipping route, data suggests.

The apparent retreat comes following attacks on two tankers in June and ahead of Iran’s seizing of the 50,000-dwt Stena Impero (built 2018) on Friday that escalated hostilities in the region.

British-flagged tankers in the area are in particularly short supply at a time when relations between London and Tehran have been super-charged by the detention of the 301,000-dwt Grace 1 (built 1997)...