Detained Iran tanker in Gibraltar had 2.1 million barrels of crude oil on it

On Friday Iran’s foreign minister said the capture of the ship will have consequences for the UK and US

(FILES) In this file photo taken on July 06, 2019 A picture shows supertanker Grace 1 off the coast of Gibraltar on July 6, 2019. Gibraltar police have arrested the Indian captain and chief officer of a seized Iranian tanker suspected of breaching EU sanctions by shipping oil to Syria, a spokesman for the Royal Gibraltar Police said on July 11, 2019. Iran demanded on July 5, 2019 that Britain immediately release an oil tanker it has detained in Gibraltar, accusing it of acting at the bidding of the United States. Authorities in Gibraltar, a British overseas territory on Spain's southern tip at the western entrance to the Mediterranean, said they suspected the tanker was carrying crude to Syria in violation of EU sanctions. / AFP / JORGE GUERRERO

Gibraltar’s chief minister has confirmed that the Iranian tanker believed to be bound for Syria that was seized off its coast by British marines last week had 2.1 million barrels of light crude oil on it.

It comes as the Royal Gibraltar Police arrested two more of the tanker's officers on Friday on suspicion of breaching EU sanctions by shipping oil to Syria bringing the total to four, including the captain and chief officer.

Earlier on Friday, Iran demanded the immediate release of the oil tanker, warning the UK: “This is a dangerous game and has consequences.”

The Grace 1 Iranian supertanker was seized off the coast of the British territory on July 4 after it was suspected of carrying crude oil to Syria, breaching EU sanctions.

The move sparked fury in Tehran, who branded the act ‘illegal’. Calling for the vessel’s release, an Iran foreign ministry spokesperson told state news agency IRNA: "The legal pretexts for the capture are not valid... the release of the tanker is in all countries' interest."

A lengthy legal battle about the seizing of the tanker could ensue, which could potentially last for months. Initially the Gibraltan government said the ship could be held for 72 hours but has since extended it to 14 days. But when that time is up, it can be extended again to 90 days or the government could look into legally seizing the ship and its cargo or possibly selling its cargo and before releasing the vessel.

Because it is rare that EU sanctions breaches have been attempted - in part due to the large fines - Grace 1's detention is somewhat of a legal grey area.

On Thursday, Gibraltan police arrested the captain and the chief officer of the seized ship. The two men, both Indian nationals, were arrested on Thursday, a spokesman for the Royal Gibraltar Police said.

On Friday two more officers were arrested, they are also Indian nationals.

The same day, the UK government said on Thursday that three Iranian vessels tried to block a British-owned tanker passing through the Strait of Hormuz, which controls the flow of Middle East oil to the world, but backed off when confronted by HMS Montrose. Iran denied the claims, saying that if it had received orders to seize any vessels it would have executed them straight away.

Iran's Revolutionary Guard Corps has said it is not behind the incident, but they warned that the US and UK would "strongly regret" capturing Grace 1.