In May, a fleet of ships set sail for fuel-starved Venezuela with Iranian gasoline, stunning international observers who wondered if the two nations would so blatantly defy U.S. sanctions efforts in a Caribbean Sea patrolled by the U.S. Navy.

Five vessels arrived without incident, greeted by an exultant Venezuelan leader.

One did not.

The vessel, the Victor 1, sat in the Gulf of Oman for more than 100 days before discharging its badly needed cargo several oceans away from its intended destination. Dozens of e-mails sent by the ship’s charterer and seen by Bloomberg show how the Victor 1’s cargo became ensnared in a payment dispute that involves little-known trading entities, allegations of corporate identity theft and, potentially, an indicted Colombian businessman accused by the U.S. of being a dealmaker for Venezuela’s President Nicolas Maduro.

The shadowy tale demonstrates both the limits and consequences of U.S. oil sanctions levied against Venezuela last year in an attempt to dislodge the autocratic regime. Years of mismanagement by the state oil company have left its refining sector in a shambles, bringing gasoline production to a near halt. That’s forced Venezuela to seek fuel from a dwindling cast of international suppliers, but also presents opportunities for companies willing to engage in trades that, while not necessarily illegal, risk the ire of the U.S., which keeps widening its net of sanctions.

“This is a cautionary tale for others willing to do business with Venezuela,” said Diego Moya-Ocampos, a political-risk consultant at IHS Markit in London. “Every drop of gasoline matters to the Maduro regime, so any losses have a huge impact on the country’s social stability.”

The Victor 1 was chartered by Imperium SA DMCC in early April to carry 295,000 barrels of fuel to Venezuela, according to e-mails seen by Bloomberg. In a separate email correspondence related to company financing, Dubai-based Imperium described itself as an oil-trading company established to export Venezuelan crude to Malaysia, Singapore, India and China. Imperium said in that email its purpose is to buy Venezuelan crude from its affiliate companies, Libre Abordo SA de CV and Schlager Business Group.

In an e-mail dated April 2, Imperium informed Iran’s state-controlled National Iranian Oil Products Distribution Company that it had arranged a vessel to load one of its cargoes of gasoline. The fuel cargo originally loaded in Iran in mid-March onto the vessel Venice 1 and then was moved April 10 onto the Victor 1 by ship-to-ship transfer in the United Arab Emirates, according to ship-tracking data. Trinidad and Tobago was listed as the vessel’s destination on a shipping manifesto. But its destination was meant to be the Venezuelan government-controlled port of El Palito, emails to the shipper show.

Payment Missing

For the next month, the shipper, Liberian-registered Ceto Shipping, and Imperium struggled to agree on where to deposit payments. Ceto sent multiple emails seeking to get paid by offering different bank accounts for deposit from Oman to Qatar, while Imperium requested Ceto provide bank accounts in Europe or Dubai. In an e-mail dated May 22, Ceto accused Imperium of not paying all of its chartering fee. In the same email, the shipper expressed concern about some of the participants involved in the cargo’s sale from Iran to Venezuela.

A representative for Ceto told Imperium it notified the National Iranian Oil Products company “we couldn’t continue this cooperation with Alex Sabb,” a possible misspelling of Alex Nain Saab Moran, who was indicted by the U.S. last year on federal money-laundering charges. He’s currently in prison in Cape Verde, where he was arrested during a flight refuelling stop. Saab’s lawyer called his detention “arbitrary and illegal” and promised to appeal an extradition order granted last month.

Around the time that the Victor 1 should have been arriving to Venezuela at the end of May, Libre Abordo filed for bankruptcy and was subsequently sanctioned by the U.S. Treasury Department. It’s not clear from the emails whether the payment dispute is the sole reason why the vessel never departed or whether Libre Abordo’s bankruptcy played any part. The only thing that’s known for certain is the badly needed product didn’t reach Venezuela.

Libre Abordo didn’t respond to repeated email requests for comment. Requests for comment sent to the email address used by Ceto in the documents went unanswered. Alexander Rodriguez, who is described as a person in charge in e-mails sent by Imperium, didn’t return calls and emails seeking comment. In separate emails to refiners in March, Rodriguez identified himself as an employee at Libre Abordo.

Corporate documents identify Giagkos Stylianou as a shareholder in Imperium. When contacted, Stylianou said he had an agreement with an undisclosed party to represent Imperium, but that he was unaware of any dealings with Iran.

“What I understood after looking into it, is that there’s someone who’s illegally using this company for his own benefit,” Stylianou said in a statement, without elaborating.

Iran’s oil ministry declined to comment when reached by phone and the foreign ministry didn’t reply to a request for comment. Venezuela’s Ministry of Information didn’t respond to a request for comment.

Five tankers carrying a total of 1.5 million barrels of gasoline arrived in Venezuela in May and June, prompting U.S. authorities to impose sanctions against their ship captains. According to the U.S. Department of Treasury, all five vessels were Iranian-flagged tankers chartered by the Islamic Republic of Iran Shipping Lines and National Iranian Tanker Company, both of which were already sanctioned by the U.S. Ship-tracking data show the Victor 1 floated off Oman for more than three months and discharged its cargo in the U.A.E. on July 23.

In July, the U.S. filed documents to seize the gasoline on board four more Venezuela-bound Iranian vessels. The transponders, or satellite signal, for all four tankers were switched off between May and early July, ship-tracking data show. Although their location is unknown, the Venezuelan government hasn’t made any announcements about their arrival and the effects of gasoline shortages are once again being felt across the country.

“Iran is the gasoline supplier of last resort,” said Moya-Ocampos. “Nobody is willing to supply Venezuela because of the reputational risk.”