Tokyo:  Radioactive water from the tsunami-hit Fukushima nuclear power plant may have leaked into the Pacific Ocean, the plant operator has said. The Tokyo Electric Power Company (TEPCO) said that around 45 tonnes of water contaminated with radioactive substances caesium and iodine had likely run into the ocean from a gutter into which water had leaked from a condensation unit.

Junichi Matsumoto, a General Manager at TEPCO, said the leaked water contained 16,000 becquerels per litre of radioactive cesium 134 and 29,000 becquerels of cesium 137, surpassing government safety limits by 267 and 322 times respectively.

Local media reports said the contaminated water may also contain other radioactive substances such as strontium, known to cause bone cancer in humans.

TEPCO officials said on Monday that contaminated water leaked from a desalination unit through a crack in a concrete wall into a gutter. The gutter connects with a drain that flows freely into the Pacific Ocean.

Sand bags were being used as an emergency means to prevent further leakage, but it could take up to three weeks to know the exact amount of leaked radioactive water.

The Japanese government on Monday halted shipments of rice from some farms in Fukushima prefecture due to the yields containing high levels of radioactive cesium.

(Agencies)