LONDON -- Among the 2.3 million people who live in the Pacific Islands and rely on the ocean for food and income, many hold concerns over Japan's plans to release more than 1 million metric tonnes of treated radioactive wastewater into the sea, The Guardian reported on Tuesday.

The water was mostly used to cool reactors after the Fukushima Daiichi nuclear plant was hit by an earthquake and tsunami in 2011 that led to meltdowns in three of its reactors, in the world's worst nuclear accident since Chernobyl 25 years earlier, it said.

The Pacific Islands Forum (PIF), the peak intergovernmental organization representing the region, has been consulting with Japan over the release for the past two years and in January said it had "grave concerns" over the plans, the report said.

Last month the PIF issued a statement drawing attention to international laws against dumping nuclear waste in the Pacific Ocean, The Guardian said.

"Our people do not have anything to gain from Japan's plan but have much at risk for generations to come," The Guardian quoted PIF Secretary General Henry Puna as saying.