TOKYO - The utility that owns the crippled Japanese nuclear reactor says that highly radioactive water has stopped leaking into the ocean.

Tokyo Electric Power Co. spokesperson Naoki Tsunoda said Wednesday the company's attempt to stem the leak by injecting 1,500 litres (400 gallons) of "water glass," or sodium silicate, and another agent near a seaside pit where the water was leaking appeared to have been successful.

The leak was discovered Saturday, and radiation of more than 7.5 million times the legal limit for seawater was found just off a tsunami-damaged nuclear plant.

The water stopped leaking at 5:38 a.m. (2038 GMT) Tokyo time, Tsunoda said.

Radiation has been seeping from the plant, raising concerns about the safety of seafood in the area.