The tanker, the Stena Impero, was seized along with its crew by Iran's Revolutionary Guards in the Strait of Hormuz on July 19 for alleged marine violations.
"After the issuing of the ruling for the end of detention of the English tanker Stena Impero this vessel will soon, and after the passing of 65 days, begin its movement from the port of Bandar Abbas toward international waters," Allahmorad Afifipour, the head of the Ports and Maritime Organisation of Iran in Hormozgan Province, told Iran's semi-official Fars news agency on Sunday, according to Reuters.
The process for the tanker to exit Iranian waters has been started, but the legal case against the ship is still open, Afifipour reportedly told Fars. The ship is currently being held off the port city of Bandar Abbas on the southern coast of Iran.
An exact release date has not yet been given by Iran, but according to a statement made to Sweden's public broadcaster and quoted by Reuters, the head of the Swedish firm that owns the vessel, Stena Bulk, said following Sunday's announcement, that the tanker could be released within hours.
"We have received information now this morning that it seems like they will release the ship Stena Impero within a few hours," Stena Bulk Chief Executive Erik Hanell reportedly told SVT. "We hope to be able to head out within a few hours, but we don't want to anticipate events. We want to see that the ship sails out of Iranian territorial waters."
But, by Sunday evening, the ship had still not been released.
A spokesperson for Stena Bulk, Will Marks, told Reuters, "The vessel is still being held and the negotiations are ongoing, and until we have official confirmation and the vessel is lifting up its anchor and sailing out of Iranian waters we can't confirm anything else."
There were 23 crew members of Indian, Russian, Latvian and Filipino nationalities aboard the Stena Impero when it was seized. On Sept. 4, seven of them were released, while the remaining crew members have reportedly remained aboard the ship.
The seizure was seen as an act of retaliation, since the British detained an Iranian oil tanker, the Grace 1, earlier that same month.
The Grace 1 was halted in the semiautonomous British territory of Gibraltar and was released in August after local authorities rejected U.S. requests to keep the tanker impounded.
When the British first seized the Iranian tanker, they were acting at the request of the U.S., who suspected that the Iranian tanker was bringing oil to Syria in violation of European Union sanctions. Iran denied the claims and assured a court in Gibraltar that the tanker would not proceed to Syria, according to Bloomberg.
News of the Sterno Impera's impending release comes at a time of heightened tensions in the Middle East.
Hours before Iran announced plans to release the British tanker, Iranian President Hassan Rohani called on Western powers to leave the security of the Persian Gulf to regional nations under Tehran's leadership, according to The Associated Press.
Separately, Rohani also promised to unveil a regional peace plan at this week's upcoming United Nations' meetings.