The central organization representing Japan's fishery cooperatives lodged a strong protest Friday over Tokyo Electric Power Co.'s failure to disclose the recent leak of radioactive rainwater from the Fukushima No. 1 nuclear plant into the sea, calling it a betrayal of fishermen and the public.

"It is undeniable that (this failure) will further spread the harmful rumor that has been troubling fishermen nationwide and will largely affect the future of the fishing industry. The anger among local fishermen who have been waiting to resume their business is immeasurable," the National Federation of Fisheries Cooperative Associations said in a statement submitted to industry minister Yoichi Miyazawa, who oversees Tepco.

On Tuesday, Tepco said it knew that a drainage ditch running near the contaminated reactor buildings has been showing high levels of radiation and that rainwater running there has been flowing into the seas since last spring.