The Japanese utility that owns the tsunami-damaged nuclear power plant says it has detected a record 740,000 becquerels per kilogram of radioactive cesium in a fish caught close to the plant.
That's 7,400 times the government limit for safe human consumption.
The bottom-dwelling fish called a greenling was found Feb. 21 in a cage set up by Tokyo Electric Power Co. inside the port next to the Fukushima Dai-ichi nuclear power plant, said a utility official who requested anonymity, citing company policy.
The March 11, 2011, earthquake and tsunami damaged the plant, causing meltdowns that spewed radiation into the surrounding soil and water.
Some experts speculate that radioactive water may be seeping from the plant into the ocean.
Most fish along the Fukushima coast are barred from market.
Explore further: TEPCO: Record high radiation level found in fish