The captain of a South Korean fishing boat admitted that his vessel trespassed into Japanese waters near South Korea’s easternmost islets of Dokdo, Seoul’s foreign ministry said Friday.

An overnight joint investigation by the two countries’ maritime police found that the 29-ton “33 Ssangyong” did not engage in illegal fishing within the Japanese exclusive economic zone.

“The South Korean Coast Guard completed its report based on the captain’s testimony early this morning,” a ministry official said.

“The captain surnamed Lee admitted that his boat entered the Japanese EEZ and is likely to be released today once he files a written guarantee that he will pay the due fines.”

Lee has to pay a fine of 250,000 yen (3.37 million won) for not complying with the Japanese demand to stop the vessel.

The “33 Ssangyong” with nine crew members aboard maneuvered 70 kilometers southeast of Dokdo on Thursday morning, entering the Japanese EEZ, and returned to South Korean waters as it was chased by four Japanese patrol boats.

The South Korean Coast Guard got to the scene after receiving a report that the fishing boat was being chased by Japanese patrol vessels and have jointly investigated the case with the Japanese maritime police since.

Seoul’s foreign ministry official said the incident was simply an accident that had nothing to do with the territorial dispute over Dokdo between Korea and Japan.

By Kim So-hyun (sophie@heraldcorp.com)