US attempting to seize Iranian oil tanker in Gibraltar ahead of planned release

Ship 'would have sailed' if not for American intervention, Gibraltan court says

The US government has applied to seize an Iranian oil tanker in Gibraltar commandeered last month by British Royal Marines, just hours before the Gibraltan government was set to release it.

In what will complicate a possible tanker swap between Britain and Tehran, the US Department of Justice applied to seize the Grace 1 tanker, which Gibraltar had said was suspected of smuggling oil to Syria in breach of European Union sanctions.

The ship was seized in a daring landing in darkness in the Mediterranean off the British overseas territory on 4 July. As tensions grew with the Islamic Republic, Iran's Revolutionary Guards seized the British-flagged Stena Impero in the Gulf on 19 July.

The Gibraltar government confirmed earlier media reports that the Justice Department had sought to extend the detention of Grace 1, prompting the Supreme Court in the territory to adjourn a scheduled decision on whether to release the ship until later in the day.

"The US Department of Justice has applied to seize the Grace 1 on a number of allegations which are now being considered," the government said in a statement, adding that the matter would be reviewed by the court at 4pm local time.

The Gibraltarian court's chief justice, Anthony Dudley, made clear that were it not for the US move, "the ship would have sailed", the Gibraltar Chronicle reported.

The Justice Department did not immediately respond to a request for comment. Britain's Foreign Office said in a statement the "investigations conducted around the Grace 1 are a matter for the government of Gibraltar" and that it could not comment further as the investigation was ongoing.

It was not immediately clear to what the Justice Department's application related.

While there was no immediate reaction from Tehran, the US move will likely further stir tensions in the Persian Gulf. Analysts had hoped the release of the Grace 1 by Gibraltar would see the Stena Impero similarly released.

Speculation on the impending release had mounted around Thursday's hearing at the Gibraltar supreme court, but a lawyer representing the territory's attorney general Michael Llamas said the US had moved at the eleventh hour.

The Chronicle reported the captain and three officers of the Grace 1 had been released from arrest on Thursday, but the report could not be confirmed. A Gibraltar government spokesman declined to comment.

Tensions have escalated in the region since US president Donald Trump over a year ago unilaterally withdrew the US from Iran's 2015 nuclear deal with world powers. The decision stopped billions of dollars' worth of business deals, largely halted the sale of Iran's crude oil internationally and sharply depreciated Iran's currency, the rial.

In recent weeks, Iran has begun to step away from the nuclear deal by increasing its production and enrichment of uranium. It has threatened to take further steps in early September if Europe cannot help it sell its oil abroad.

Additional reporting by agencies