A Greek shipping company has pleaded guilty to smuggling sanctioned Iranian crude oil and agreed to pay a $2.4 million fine, newly unsealed US court documents seen Thursday by The Associated Press show.

The now-public case against Empire Navigation, which faces three years of probation under the plea agreement, marks the first public acknowledgement by US prosecutors that America seized some 1 million barrels of oil from the tanker Suez Rajan.

The saga surrounding the ship further escalated tensions between Washington and Iran, even as they work toward a trade of billions of dollars in frozen Iranian assets in South Korea for the release of five Iranian Americans held in Tehran.

The court filings also shed light on the covert world of Iranian crude oil smuggling in the face of Western sanctions since the collapse of its 2015 nuclear deal — an operation that has only grown in scale over this year.

The US and its allies have been seizing Iranian oil cargoes since 2019.

That’s led to a series of attacks in the Mideast attributed to the Islamic Republic, as well as ship seizures by Iranian military and paramilitary forces that threaten global shipping through the Strait of Hormuz, the narrow mouth of the Persian Gulf through which 20% of the world’s oil passes.

Attention began focusing on the Suez Rajan in February 2022, when the group United Against Nuclear Iran said it suspected the tanker carried oil from Iran’s Khargh Island, its main oil distribution terminal in the Persian Gulf.

Satellite photos and shipping data analyzed at the time by the AP supported the allegation.

The newly unsealed court documents rely on satellite images, as well as documents, to show that the Suez Rajan sought to mask its loading of Iranian crude oil from one tanker by trying to instead claim the oil came from another.

For months, the ship sat in the South China Sea off the northeast coast of Singapore before suddenly sailing for the Texas coast without explanation.

The vessel discharged its cargo to another tanker, which released its oil in Houston in recent days.

The court documents seen Thursday confirm the US government seized the oil.

A lawyer for Empire Navigation, Apostolos Tourkantonis, pleaded guilty to a single charge of violating the sanctions on Iran. Empire, based in Athens, Greece, did not immediately respond to a request for comment early Thursday.

The court documents seen Thursday confirm the US government seized the oil.

The US Treasury has said Iran’s oil smuggling revenue supports the Quds Force, the expeditionary unit of the Revolutionary Guard that operates across the Mideast.

The Guard is suspected to be closely involved in the trade, involving hundreds of vessels that try to mask their movements and can hide their ownership through foreign shell companies.

But the Suez Rajan case was unique at the time of the transfer because it was owned by the Los Angeles-based private equity firm Oaktree Capital Management.

That likely gave American prosecutors an edge in pursuing this case.

Oaktree, which has repeatedly declined to discuss the case, sold the vessel fully to Empire in late May.

Mark Wallace, a former US ambassador to the United Nations under President George W. Bush who heads United Against Nuclear Iran, praised Empire Navigation for agreeing to the plea.

He described Iran’s oil smuggling as a “mob-like” operation and urged others to abandon the trade.