A group of opposition lawmakers who visited Japan last week said Monday they conveyed South Koreans' concerns over Tokyo's plan to release radioactive water from the crippled Fukushima nuclear power plant into the sea.

Four lawmakers from the main opposition Democratic Party (DP) paid a three-day visit to probe the radioactive water release plan, and hold meetings with municipal lawmakers and residents of the Fukushima area. They also requested Tokyo Electric Power Co., the operator of the Fukushima plant, share information related to the matter.

"We were able to draw the attention of both South Korean and Japanese people to the issue once again," Reps. Wi Seong-gon said. He claimed all residents they met were opposed to the release plan.

"People say there is an alternative of making a water tank on land and storing the water there. It's a matter of cost," Wi added.

Rep. Yang Yi-wonyoung said the DP lawmakers confirmed the contaminated water contains plutonium and other chemicals even though it went through liquid processing systems, and a report by the International Atomic Energy Agency has no expression that Japan's plan is "credible."

The DP lawmakers plan to push for a special parliamentary body or a parliamentary investigation to deal with the matter and explore cooperation with other countries to create an international consultative body on the issue.

"Until when will the government pussyfoot around for the Japanese government in front of a matter that concerns the safety and lives of our people?" DP floor leader Park Hong-keun said, urging the government to take the matter to the International Tribunal for the Law of the Sea.

Park also called on Japan to suspend its plan, which he said does not guarantee safety and is opposed by neighboring countries. (Yonhap)