An Iranian tanker caught in the standoff between Tehran and the West shifted position on Friday but remained at anchor off Gibraltar on Sunday.
Her AIS data does not indicate any planned voyage, despite her detention order being lifted on Thursday by authorities in Gibraltar.
Gibraltar’s chief minister, Fabian Picardo, said earlier that the tanker was free to leave as soon as it had organised its logistics.
“Could be today, could be tomorrow,” Picardo told BBC Radio on Thursday.
It has been reported that the United States made a last ditch legal appeal to hold the tanker, it’s unclear whether that is the reason for the delay.
Gibraltar authorities could not be reached for comment.
The Grace 1 was seized by British Royal Marines at the western mouth of the Mediterranean on July 4 on suspicion of violating European Union sanctions by taking oil to Syria, a close ally of Iran.
That kicked off a sequence of events that saw Tehran seize a British-flagged oil tanker in the Gulf two weeks later, heightening tension on a vital international oil shipping route.
That tanker, the Stena Impero, is still detained.
Gibraltar said it had found evidence confirming the Grace 1 was carrying its cargo – 2.1 million barrels of oil – to the Baniyas refinery in Syria. Tehran denies that.
Gibraltar Chief Minister Picardo said on Thursday he had agreed to release the ship after receiving written assurances that the cargo would not go to Syria.
Tehran also denied that it had made any commitments to secure the release of the tanker.
Calling the US attempt to block the tanker “piracy” and denying any commitments had been made to secure its release, Iranian officials have said Grace 1 would sail shortly after the 25-member crew made preparations including refuelling.
“Based on the owner’s request, the oil tanker Grace 1 will depart for the Mediterranean after being reflagged under the Iranian flag and renamed Adrian Darya after preparing for the journey,” Iranian state television quoted Jalil Eslami, deputy head of the country’s Ports and Maritime Organisation, as saying.