A South Korean court has jailed the captain and a crewman of a Hong Kong-registered supertanker for involvement in Korea's largest oil spill, sparking outrage from the owner and international shipping groups. Captain Jasrit Chawla and engineer Syam Chetam, both Indian nationals, were sentenced to jail terms of 18 months and 8 months for criminal negligence and fined 20 million won (HK$107,700) and 10 million won respectively. Daejeon District Court, which heard the case on appeal, cited inadequate damage-control efforts. Both men have been detained since the spill, despite being found innocent of criminal negligence charges in June. Prosecutors appealed against that decision. A spokesman for Hebei Ocean Shipping Company, which owns the tanker Hebei Spirit and is based in Qinhuangdao , Hebei , said it was shocked by the decision. 'This decision was not reached using due process and was not done in collaboration with all stakeholders,' the spokesman said. 'They have not consulted anyone but themselves. This goes against international convention.' He said this was surprising given that South Korea was the world's second-biggest ship builder and that the case was being closely watched by the shipping community. Critics of the prosecution have pointed out that the tanker was at anchor on December 7 last year off Daesan Port in the Yellow Sea when a Samsung Heavy Industries-owned crane barge became disconnected from its tugs and collided with the single-hulled tanker in heavy seas, ripping three holes in it. The tanker spilled 11,000 tonnes of crude oil - one-third the size of the 1989 Exxon Valdez disaster - into pristine coastal waters. The cleanup, aided by troops and a million volunteers, cost US$500 million. In yesterday's decision, the Samsung barge captain was also jailed for 18 months, while the two tug masters had previous jail terms reduced. Samsung and Hebei Ocean Shipping were both fined 30 million won. Intertanko, an association representing 80 per cent of all independent tanker owners, expressed 'dismay' at the verdict. In an open letter to South Korean President Lee Myung-bak published in The Korea Times, it charged that data supplied to the court by the Korean Maritime Safety Tribunal was not up to international standards. International Transport Federation Maritime official Stephen Cotton said on the ITF Global website that he was asking the federation's 656 member unions to mobilise. 'That these men are in detention when they have been proved blameless is both impossible to understand and deeply injurious to South Korea's image abroad,' he wrote. Hebei Ocean Shipping said it found the reasons for the decision technically flawed. It said it was considering its options. In September, Roberto Giorgi, president of ship management group V Ships, which employs the ship's officers, told Lloyd's List maritime newspaper that he believed Samsung lawyers, prosecutors and investigators had colluded.