An Empire Navigation vessel has taken the first load of a controversial crude cargo on a seized suezmax to a terminal in Houston, vessel tracking data shows.

The ship-to-ship transfer marks the latest step in the drama over the cargo of suspected Iranian oil on board the 159,000-dwt Suez Rajan (built 2011), which is also owned by Greece’s Empire Navigation.

Satellite tracking data from VesselsValue and Clarksons’ Sea platform both show the 50,000-dwt MR Euphrates (built 2008) moored in Houston’s Buffalo Bayou on Tuesday near Energy Transfer’s dock at the port.

That came after the MR product tanker pulled up to the Suez Rajan late Saturday for a ship-to-ship transfer, putting an end to a wait for a way to offload the cargo roughly a month after reports emerged that companies were hesitant to touch the disputed oil.

Energy Transfer did not immediately respond to a request for information on whether the vessel is slated to unload there, and the vessel is not named on the port’s schedule. The US Justice Department declined to comment on the Suez Rajan, while Empire Navigation has not responded to TradeWinds’ request for comment for several months.

The MR Euphrates is listed as laden.

It is possible that US authorities are awaiting a court order to formally seize the cargo on board the product tanker.

As TradeWinds has reported, the crude on the Suez Rajan has long been the subject of legal disputes over its suspected Iranian origins.

After it was held up for more than a year at a Singapore anchorage, US officials reportedly seized the tanker off the coast of Malaysia and redirected it to its current location at the Gulf Offshore Lightering Area off Galveston. It has been waiting there since May.

Iran responded to the seizure with a retaliatory seizure of its own, grabbing the Chevron-chartered, 159,000-dwt suezmax tanker Advantage Sweet (built 2012) in April.

Ahead of the arrival of the MR Euphrates, US military officials warned shipping in the Strait of Hormuz last week over the potential for more Iranian seizures.

It will take two or three more ship-to-ship transfers for a vessel as small as the MR Euphrates to offload the crude from the Suez Rajan.

But US officials likely had few options available to them, after Houston lightering companies reportedly were hesitant to get involved with moving the oil.

Earlier this month, US senators Joni Ernst and Richard Blumenthal, joined by other lawmakers, urged the administration of US President Joe Biden to take action on the cargo.

“It is imperative that the administration make clear that Iran and designated foreign terrorist organisations cannot prevent our government from carrying out legitimate law enforcement operations,” they wrote, according to Reuters.