The US has seized more than 500,000 barrels of Iranian oil after a ship-to-ship transfer involving a Euronav tanker.

Details of the seizure were revealed in court documents after nine people were charged in connection with a “global, long-running” $1bn Iranian oil-smuggling racket dating back to the reimposition of sanctions by the US in 2018.

The smuggling ring, which involved key players at the heart of the Iranian regime, was accused of trying to ship oil from Iran to Syria, Russia and China using faked documents, spoofing tracking data and disguising the origin of cargoes.