A Chinese fisherman was jailed for 30 years on Thursday for murdering a South Korean coastguard officer during an operation to stop illegal fishing, court authorities said.
Cheng Dawei, a 43-year-old fishing boat skipper, was also fined 20 million won ($17,540) by the court in the western port city of Incheon.
The skipper was accused of fatally stabbing one officer with a knife and seriously wounding another on December 12, after officers boarded his boat inside South Korea's exclusive economic zone in the Yellow Sea.
It was the second time a South Korean coastguard had died at the hands of Chinese fishermen in less than four years and the incident sparked widespread public anger.
Seoul urged Beijing to take stronger action against illegal fishing and lawmakers sought tougher punishment of violators.
There were no immediate details of the verdict or of the ruling on nine of Cheng's crew members who were charged with obstructing the coastguard raid.
South Korea has announced plans to spend 932.4 billion won between 2012 and 2015 on better equipping its forces as part of a crackdown on poaching, including issuing more firearms.
It seized 475 boats last year compared with 370 in 2010. When stopped, Chinese crews in the past have often fought back with metal pipes and knives or lashed their boats together to deter boarders.
During a visit to Beijing by the South's President Lee Myung-Bak in January, the two nations agreed to regular consultations to resolve the issue of illegal fishing by Chinese boats.