The Panama-registered oil tanker, operated by National Iranian Tanker Co, was sailing from Iran to South Korea, carrying 136,000 tonnes of condensate, when it collided with the ‘CF Crystal’, on 6 January 2018, about 160 nautical miles off the coast, near Shanghai and the mouth of the Yangtze River Delta, and went ablaze. After burning for more than a week, it eventually sank, causing one of the worst oil spills in over 30 years.

The ship was carrying nearly 1 million barrels of ultra-light crude and has created four separate slicks covering a total area of 100 square km (or 39 square miles), which is almost equivalent to the size of Paris.

At the time of the accident, the ship was carrying a total of 32 crew members, all of whom are presumed as dead, with only three bodies recovered so far.

Earlier in May, Iranian and Panamanian representatives of the investigating committee, as cited in local media, seemed to blame mostly the Crystal's change of direction some minutes before the incident, while representatives from China believed that both ships were equally responsible.

After months of scrutiny by the three-country joint investigation group, related parties have reached consensus on the basic facts around the accident, including the properties of Sanchi's cargo, identification of the crew, time of the collision and process of the accident, according to the latest update from Xinhua news agency. However, differences remain concerning the direct cause of the accident, according to the report.

China, which led the investigation, has submitted the report to the IMO.