BEIRUT (REUTERS) - The black boxes for the tanker Sanchi and the freighter CF Crystal, the two vessels that collided in the worst oil ship disaster in decades, have been opened, the Iranian Students' News Agency (ISNA) reported on Wednesday (Jan 24).

Officials from China, Iran, and Panama were present when the black boxes were opened, Hadi Haqshenas, maritime affairs deputy at Iran's Ports and Maritime Organisation, was quoted as saying by ISNA. The report did not say where that happened.

"Clarifying the ultimate results of the deciphering process takes time and it could take months," Haqshenas said, according to ISNA.

The Sanchi, run by Iran's top oil shipping operator, collided with the CF Crystal about 160 nautical miles off the coast of China near Shanghai and the mouth of the Yangtze River Delta on Jan 6.

The Panama-registered tanker was sailing from Iran to South Korea, carrying 136,000 tonnes of condensate, an ultra light crude, equivalent to just under 1 million barrels, worth about US$60 million (S$78.7 million).

The Sanchi sank on Jan 14 after burning for several days. The entire crew of 30 Iranians and two Bangladeshis, are presumed dead.