No large oil spill has been detected so far from the 'Sanchi' which was still alight and amidst bad weather - with waves of up to four meters, which was affecting the rescue work. The heavy winds, rain and high waves continued to hamper efforts to contain the fire. The tanker had on board 136,000 tonnes of condensate, which is an ultra-light version of crude oil. Experts at the scene believed that, given the wave conditions, no more than 1% of the condensate was on the surface of the water. The tanker, run by Iran's leading oil shipping operator, has on board about one million barrels of condensate, which at current prices is worth roughly $60m (£44m). The Sanchi will also be carrying a certain amount of heavy - and toxic - shipping fuel. A formal accident investigation, involving several government departments, would start on Jan 9, officials said.