Sweden has reportedly received "very strong indications" from Iran that it will release the British-flagged Stena Impero oil tanker sometime in the coming days.
Sweden's foreign ministry believes that the ship, which is operated by a Swedish firm, will be set free in the near future, according to Swedish public television.
The report emerged after Javad Zarif, Iran's foreign minister, met with his Swedish counterpart, Margot Wallstrom, in Stockholm earlier this week. The Iranian minister also met with the chief executive of Stena Bulk, the ship's operator.
A spokeswoman for Sweden's foreign ministry would not confirm or deny the STV report.
"We look positively at what Foreign Minister Zarif himself has said publicly about hopes for a possible quick solution for Stena Impero, but we do not disclose what is said in the meetings," the spokeswoman said.
The Stena Impero was seized by Iran's Revolutionary Guard on July 19 in apparent retaliation for Royal Marines seizing the Iranian Grace 1 tanker off the coast of Gibraltar on July 4.
The Grace 1, renamed the Adrian Darya 1, was released from Gibraltar over the weekend. British officials hoped its release would pave the way for the release of the Stena Impero.
Iran has so far given no indication when, or if, it plans to release the British-flagged tanker.
Iranian officials initially indicated that the Stena Impero had been seized in response to the Grace 1's seizure but now claims that the ship violated maritime rules in the Persian Gulf.
Tehran has said that a court in the southern port of Bandar Abbas will decide the ship's fate. British officials believe Tehran is hiding behind legalism when the ship's seizure and release are in reality in the hands of political decision makers.
The US has continued to pursue the Grace 1 after it left Gibraltar and has warned European states not to give the ship safe harbour as it sails east across the Mediterranean.
That warning has now been extended to any European shipping firms that might interact with the tanker. "The shipping sector is on notice that we will aggressively enforce US sanctions," a US official told Reuters.