The Adrian Darya, formerly called the Grace 1, was released from detention off Gibraltar after a five-week standoff over whether it was carrying Iranian oil to Syria in violation of European Union sanctions in mid-August which Iran denied.
The crew of the supertanker updated its listed destination in its Automatic Identification System to Mersin, Turkey, a port city in the country's south and home to an oil terminal.
Previous data had shown that the vessel, which carries 2.1 million barrels of Iranian crude oil worth some $130 million, was heading to the port of Kalamata in Southern Greece. But new data from MarineTraffic on Saturday showed the vessel will now sail past Greece through the Mediterranean and dock at the southern Turkish port of Mersin.
The ship-tracking website showed the Adrian Darya's position as just south of Sicily in the Mediterranean Sea. At current speeds, it estimated the Adrian Darya would reach Mersin in about a week.
The United States, which claims the tanker is controlled by the Iran’s Islamic Revolution Guards Corps has told countries in the region not to assist it.
The Adrian Darya had put its intended destination as Kalamata, Greece, even though the port did not have the infrastructure to offload oil from the tanker. The US State Department then pressured Greece not to aid the vessel.
The Adrian Darya's detention and later release by Gibraltar have added fuel to the growing tensions between Washington and Tehran, after Trump unilaterally withdrew America from Iran's 2015 nuclear deal with world powers over a year ago.
The US reimposed and created sanctions largely blocking Iran from selling crude oil aboard, a crucial source of hard currency for the Islamic Republic.
AP and Reuters contributed to this story.