(Bloomberg) -- Mexican authorities say an oil trader at state-owned Petroleos Mexicanos acted improperly when he struck a deal in 2017 to store crude at sea after Hurricane Harvey.

Emilio Sampayo, who recently resigned as deputy director of crude trading at Pemex’s trading arm PMI is being targeted for authorizing payments totaling $1.14 million to keep a million barrels of oil floating in a tanker for 38 days until a buyer could take delivery, according to people familiar with the matter. Pemex auditors flagged the transaction to the federal comptroller, which ruled that Sampayo acted improperly by paying storage fees not typically shouldered by PMI, said the people, who asked not to be named because the information isn’t public. 

A federal court has since upheld the comptroller’s ruling, which Sampayo can appeal, said two of the people.

The probe highlights the growing tension between PMI and Pemex’s auditing unit amid an effort by Mexico President Andres Manuel Lopez Obrador to crack down on corruption within the government. PMI traders have been the focus of several internal audit investigations, according to two people familiar with the matter. The unit is slated for elimination as part of the president’s plan to end oil exports and consolidate the energy industry.

At the center of the latest investigation is a contract between Pemex and Chevron Corp. signed in September 2017, after Hurricane Harvey ravaged the Gulf Coast and shuttered at least 17 US refineries. The lack of refining capacity left Pemex with nowhere to send its barrels, forcing the company to shut in crude production.

To keep the oil flowing, PMI asked Chevron, owner of five refineries in the US, to take 1 million barrels of its flagship Maya crude oil two months ahead of schedule, according to a document seen by Bloomberg. Chevron wasn’t in a position to process the barrels right away so, in an unusual move, PMI agreed to cover the demurrage fees, which are incurred when a tanker sits on the water for longer than initially agreed. Over 38 days, those penalties amounted to $1.14 million. 

Although Sampayo wasn’t the only trader involved in the deal, he executed the payments. 

Pemex and Chevron aren’t under investigation, two people said. Chevron, Pemex and Sampayo didn’t immediately respond to multiple requests for comment.

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