Japan's nuclear regulators have approved a plan to release into the ocean water from the wrecked Fukushima Dai-ichi nuclear power plant, the government said today.

The water, used to cool reactors in the aftermath of the 2011 nuclear disaster, is being stored in huge tanks in the plant and amounted to more than 1.3 million tonnes by July.

The regulators deemed it safe to release the water, which will still contain traces of tritium after treatment, the foreign ministry said in a statement.

Plant operator Tokyo Electric Power Company (Tepco) will face additional inspections by regulators, it added.

Tepco plans to filter the contaminated water to remove harmful isotopes apart from tritium, which is hard to remove.

Then it will be diluted and released to free up plant space and allow decommissioning to continue.

The plan has encountered stiff resistance from fishing unions in the region which fear its impact on their livelihoods. Neighbours China, South Korea, and Taiwan have also voiced concern.

- Reuters