Gibraltar's Supreme Court ruled Friday (July 19th) that a seized Iranian tanker suspected of breaching sanctions by shipping oil to Syria can be detained for 30 more days, the British territory's attorney general said.

The Grace 1 supertanker, carrying 2.1 million barrels of oil, was intercepted by British Royal Marines and Gibraltar's police on July 4th as it transited through waters claimed by Gibraltar, located on Spain's southern tip, AFP reported.

An initial order by the court authorising the detention of the vessel would lapse after Friday. The order can be renewed for up to 90 days.

"We look forward to continuing to work constructively and positively with officials of the Islamic Republic of Iran to facilitate the release of the Grace 1 pursuant to the satisfaction of all legal requirements," Gibraltar's Chief Minister Fabian Picardo told the territory's parliament.

Picardo said Thursday he had a "constructive and positive" meeting with Iranian officials in London aimed at defusing tensions around the detention of the tanker in the British territory's waters.

Gibraltar and US officials believed the tanker was destined for Syria to deliver oil, in violation of separate sets of EU and US sanctions.

Iran has reacted with fury, warning it would not let the interception go unanswered.

Last week, a British warship in the Gulf warned off armed Iranian boats that tried to stop a UK supertanker. London has since announced the deployment of two more warships to the Gulf region for the coming months.