"The Adrian Darya oil tanker finally docked on the Mediterranean coast...and unloaded its cargo," Foreign Ministry spokesman Abbas Mousavi was quoted as saying by Iran's state news agency IRNA, Sunday.
The remarks were made soon after a satellite image of the ship being very close to Tartus, Syria circulated by an American space infrastructure company.
The ship was renamed from Grace 1 during its detention off Gibraltar, and was released in August after a five-week standoff over allegedly breaching EU sanctions.
Gibraltar agreed to free the Adrian Darya 1, after allegedly receiving assurances from Tehran that the ship would not go to Syria. Tehran later denied it made any promises about the ship's destination.
The ship changed several destinations and was later photographed by a satellite near the Syrian port of Tartus.
In the end of August, the US blacklisted the ship over enabling the Islamic Revolutionary Guard Corps-Qods Force (IRGC-QF) to ship and transfer large volumes of oil, thus promoting terrorism.
Maritime tracking service TankerTrackers was quoted as saying by local media Sunday night that the Adrian Darya was off the coast of Syria's Tartus, but had not unloaded the oil.