Gibraltar police have arrested the master of a tanker at the centre of a simmering political dispute between the UK and Iran.
It comes as British ships operating in the Gulf have been put on the highest state of alert amid fears they will be targeted by Iran.
British Royal Marines stormed the 301,000-dwt Grace 1 (built 1997) last week and seized the ship on suspicion of shipping oil to Syria.
The move ignited tensions between Britain and Iran at a time shipping was already on high alert following June attacks on two tankers in the Strait of Hormuz.
Earlier today a British warship thwarted an attempt by three Iranian boats to "impede" the passage of a BP tanker through the Strait of Hormuz.
Now Gibraltar police have confirmed the arrest of the captain of the Grace 1 as it continues an investigation into the tanker.
They explained the action followed a protracted search of the vessel where documents and electronic devices have been seized and examined.
Since the Ukrainian-owned Grace 1 was seized, British and Iranian officials have been trading warnings in a public war or words.
Jeremy Hunt, who is challenging Boris Johnson for the leadership of the UK's ruling Conservative party, described Iran’s attempted blockade of the 185,000-dwt British Heritage (built 2017) as a "concerning development”.
“I'm very proud of the Royal Navy and the role they played in keeping British asset, British shipping safe,” he said, according to ITN.
"We are continuing to monitor the situation very, very carefully.”
