Terrifying footage has been released by Iran showing a group of commandos chasing down the tanker – heading for Saudi Arabia – in the Strait of Hormuz last night.
The clip shows the marine officers, all masked, abseiling from a helicopter onto the deck of the British Stena Imperio, which had 23 crew on board, on Friday.
Gunboats also joined the raid on the tanker, which is registered in the UK, claiming it had turned off its tracker and ignored warnings.
After storming the ship, it was diverted off course towards Iran and is now thought to be moored on the country’s Qeshm Island.
A UK warship reportedly sped to help the tanker, but arrived 10 minutes too late as by that time the seized tanker had entered Iranian waters.
The UK has since warned of “serious consequences” following Iran’s actions which have sparked a fresh Gulf crisis.
Although the ship’s crew – of Indian, Russian, Latvian and Filipino nationality – are said to be safe and in good health, British Foreign Secretary Jeremy Hunt said Iran’s move was in “clear contravention of international law”.
He also said today that the move “raises very serious questions about the security of British shipping and indeed international shipping in the Strait of Hormuz.”
According to Mr Hunt, the vessel had been surrounded by four vessels and a helicopter as it passed Iran after departing from the UAE.
Tracking data showed the ship suddenly steering off course in the middle of its journey after being seized in the Gulf.
The seizure comes after Royal Marines abseiled from a helicopter off Gibraltar earlier this month seize the Grace 1 Iranian tanker, suspected of transporting crude oil to Syria.
The move sparked fury from Iran as officials threatened to retaliate – resulting in last night’s actions.
A spokesman for the Iranian Revolutionary Guards claimed today that the UK sent two helicopters to harass Iranian troops as they seized the tanker last night.
Despite the “resistance and interference” of the British warship, the Stena Impero was brought to the shore, Ramezan Sharif, a Guards spokesman said.
Iran has claimed that the tanker violated maritime regulations in the Strait of Hormuz and got into an accident with an Iranian fishing boat. Yet this has been denied by the UK.
The strait, between Iran and the Arabian peninsula, is the sole outlet for exports of the vast majority of Middle Eastern oil, and the seizure sent oil prices sharply higher.