royal navy patrol grace 1
© REUTERS/Jon Nazca
A Royal Navy patrol vessel guards the oil tanker Grace 1, after it was seized off Gibraltar, July 20, 2019
The US Department of Justice has applied to seize the Iranian supertanker Grace 1 in Gibraltar, just hours before the Gibraltar Government was poised to release it.

Gibraltar had been due to lift the detention on the ship this morning but the move by the US means the decision has now been adjourned until 4pm today.

The developments were revealed by Joseph Triay, the lawyer for Attorney General Michael Llamas QC, during a short hearing in the Supreme Court of Gibraltar.

Mr Triay said: "This application was to have taken a very different turn. It was to have been an application for no further order of detention."

The grounds for the US application are not clear at this stage but the court was told it was a request from the Department of Justice for mutual legal assistance.

The case has now been adjourned until 4pm this afternoon while Gibraltar's authorities consider the US application.

Speaking in court, Chief Justice Anthony Dudley made clear that were it not for the US move, "the ship would have sailed."

After the hearing, a spokesman for the Gibraltar Government confirmed the US move.

"The US Department of Justice has applied to seize the Grace 1 on a number of allegations which are now being considered," the spokesman said.

"The matter will return to the Supreme Court of Gibraltar at 4pm today."

In a separate development, a spokesman for the Gibraltar Government confirmed that the captain and three officers of the Grace 1 had been released from arrest.

The Grace 1 was seized in British waters around Gibraltar on July 4 on suspicion it was shipping 2.1m barrels of crude oil to Syria in breach of EU sanctions.

The UK and Gibraltar insist the Grace 1 was stopped because of its destination and not because of the Iranian origin of its cargo. EU sanctions prohibit the direct or indirect supply of any economic resources including crude oil to Syria.

But two weeks after the Grace 1 was boarded by Gibraltar law enforcement agencies supported by British Royal Marines, Iran's Revolutionary Guards seized a British tanker, the Stena Impero, near the Strait of Hormuz.

The UK sees that as a tit-for-tat move and says there is no parallel between the detention of the Grace 1 in British waters and Iran's decision to capture the Stena Impero in international waters.