The United States has expressed concern to India that it was used earlier this year to export fuel made from Russian crude to New York through high-seas transfers, a top Indian central banker said on Saturday.

U.S. sanctions on Russia for its February invasion of Ukraine prohibit imports to the United States of Russian-origin energy products including crude oil, refined fuels, distillates, coal and gas.

“You know that there are sanctions against people who are buying Russian oil, and this was reported to us by the U.S. Treasury,” Reserve Bank of India Deputy Governor Michael Patra told an audience of government officials and figures in finance and banking.

“It turns out, an Indian ship met a Russian tanker in mid-seas, picked up oil in the mid-seas, came to a port in Gujarat, it was processed in that port and converted into a distillate which actually goes into making single-use plastic,” Patra said at the event in Odisha state, held to celebrate 75 years of India’s independence.

“The refined output was put back on that ship and it set sail without a destination. In the mid-seas it received the destination so it reached its course, went to New York. So that’s the way war works. It works in strange ways.”

Patra did not name the ship or give any other details.

The U.S. embassy in New Delhi had no comment.

India, the world’s third-biggest oil importer and consumer, has become one of the biggest importers of Russian oil since the invasion of Ukraine, having bought very little of it previously.

Russia is traditionally India’s biggest supplier of military hardware, and New Delhi has not condemned Moscow’s aggression towards Ukraine, though it has called for an end to violence.