A supertanker owned by a subsidiary of COSCO Shipping Tanker (Dalian), under U.S. sanctions for allegedly transporting Iranian oil, has docked in Singapore to discharge Middle East crude, shipping data on Refinitiv Eikon showed on Thursday.

The Coswisdom Lake, a very large crude carrier (VLCC) capable of holding 2 million barrels of oil, docked at Exxon Mobil Corp’s terminal on Jurong Island late on Wednesday.

The tanker is owned by Pan Cosmos Shipping & Enterprises Co, which is a fully owned subsidiary of COSCO Dalian, a document issued by Cosco Shipping Energy Transportation on Oct. 1 shows.

“This discharge operation is in compliance with U.S. laws. ExxonMobil follows the law everywhere we operate and we are in full compliance with the sanctions,” the U.S. company said in an e-mail statement.

In one of the biggest sanctions actions taken by the U.S. government since its crackdown on Iranian oil exports, Washington on Sept. 25 announced sanctions on Chinese tanker companies, including COSCO Dalian, for alleged involvement in the transportation of oil from Iran.

Coswisdom Lake loaded crude from Qatar and Abu Dhabi around mid-September and arrived in Singapore on Sept. 30, shipping data showed.

The tanker left Singapore on Oct. 6 without discharging its cargoes and sailed in the South China Sea for a couple of days before heading back to Jurong Island on Wednesday, tracking data showed.

The absence of COSCO Dalian’s supertankers, which makes up 3.3% of the global VLCC fleet, has driven up global freight rates.