The United States has blacklisted the Iranian oil tanker Adrian Darya and its captain following repeated warnings over its oil cargo worth around $140 million. Previously known as Grace 1, the ship has been bouncing around the Mediterranean after being held for six weeks by Gibraltar on suspicion its cargo was bound for Syria. Despite Washingtons efforts to keep it detained, it was released by the British territory and its every move is being followed with intense speculation. The US Department of Treasury on Friday said the vessel is "blocked property" under an anti-terrorist order, and "anyone providing support to the Adrian Darya 1 risks being sanctioned". The ships captain, Akhilesh Kumar, a 43-year-old Indian mariner from Patna, was also blacklisted under the order, which generally prohibits dealings with blocked property by US persons. Lebanon had earlier dismissed Turkish claims that it would receive the ship, which has a cargo of 2.1 million barrels. While Iran has denied selling the oil to its Damascus ally, experts said the likely scenario was for a ship-to-ship transfer, with a Syrian port as the final destination. Maritime traffic monitors had shown that the Adrian Daryas latest listed destinations, which are not necessarily the next approved port of call, were in Turkey. After tracking sites showed Mersin as its destination, it then switched to Iskenderun, prompting a reaction from Turkeys foreign minister Friday. "This tanker is not heading actually to Iskenderun (in Turkey), this tanker is heading to Lebanon," Mevlut Cavusoglu said during a visit to Oslo. Lebanon swiftly dismissed the scenario, stressing that it never buys crude oil because it simply does not have refineries. According to maritime traffic monitoring websites, the huge tanker is currently just west of the island nation of Cyprus. But US Secretary of State Mike Pompeo said in a tweet late on Friday: "We have reliable information that the tanker is underway and headed to Tartus, Syria." Pompeo had earlier said that if the tanker went to Syria, Washington would take every action it could consistent with US sanctions. Iran said Monday it had "sold the oil" aboard the tanker and that the owner will decide the destination. It did not identify the buyer or say whether the oil had been sold before or after the tankers detention in the Strait of Gibraltar, on Spains southern tip. The ship was seized by Gibraltar police and British special forces on July 4 and held on suspicion of shipping oil to Syria in breach of European Union sanctions. But Iran denied the charge and said it could not name the actual destination due to United States "economic terrorism" and its sanctions on Irans oil sales.