Komeito leader Natsuo Yamaguchi said Sunday it would be better not to start the planned release of treated water into the sea from the crippled Fukushima No.1 nuclear power plant during the upcoming swimming season.

"It's important not to invite negative rumors," Yamaguchi told reporters in the city of Fukushima. Komeito is the coalition partner of the ruling Liberal Democratic Party.

The government plans to start releasing the once-contaminated water from Tokyo Electric Power Company Holdings' plant in Fukushima Prefecture this summer. The facility was the site of the March 2011 triple meltdown.

"I ask the government to decide on the timing carefully," Yamaguchi said. "I want the government to first give detailed explanations on the safety (of the treated water) to the Japanese public and the international community to ensure widespread understanding."

Referring to the continued opposition from local fishermen, Yamaguchi said he hopes the government will explain the water release plan thoroughly without rushing.