Japan PM asks minister to apologise over Fukushima wastewater comments

Japan's Prime Minister Fumio Kishida has ordered his fisheries minister to apologise for referring to treated radioactive water being released from the Fukushima Nuclear Power Plant as "contaminated" and told him to retract his remark.

"It's deeply disappointing that he made such a remark. I've instructed Minister Nomura to issue an apology as well as retract what he said," Kishida said when asked for comment on Thursday.

Fisheries minister Tetsuro Nomura called the treated radioactive water "contaminated" when speaking to reporters earlier in the day following a meeting with Kishida.

He said his discussions with the premier involved "the evaluation of the contaminated water" after its release into the Pacific.

Nomura later apologised and retracted the comment but said he would not resign over it, the Jiji news service reported.

Japan is calling the water it is releasing into the ocean "ALPS treated water" to differentiate it from the contaminated water held in tanks around the wrecked plant site.

ALPS stands for "Advanced Liquid Processing System", a system aimed at removing most radioactive elements from the water except for tritium before it is released into the ocean as "treated" water.

Because tritium, a radioactive isotope of hydrogen, is difficult to separate from water, the Fukushima wastewater is diluted until tritium levels fall below regulatory limits.

Japan's fisheries agency said tests of fish from near the plant on Saturday found no detectable levels of tritium.