TankersTracker, an oil-tanker tracking company, says six million barrels of Iran’s seized oil, worth an approximate $600 million, is being shipped “quietly” from the Atlantic Ocean toward U.S. ports.

The company has not provided further details, but Voice of America on Shahrivar 28 for the first time reported, based on analysis of maritime data on the movement of the seized tanker “Majestic X,” that it was carrying 1.88 million barrels of Iranian oil worth an approximate $200 million toward Texas.

The tanker was stateless and listed in the United States sanctions. It was seized in the Indian Ocean in Farvardin this year.

Maritime data on Thursday shows that the “Majestic X” tanker is currently moving north, off the vicinity of the coastal waters of South America.

So far, U.S. and Islamic Republic officials have not responded to the issue.