Tokyo Electric Power Co. found record high levels of radioactive cesium in fish it caught for tests within 20 kilometers of the coast from the crippled Fukushima Dai-Ichi nuclear plant.

The utility detected a combined 25,800 becquerels per kilogram of cesium 134 and cesium 137 in a greenling caught on Aug. 1, it said yesterday in a statement. That beat the previous high of 18,700 becquerels per kilogram found in cherry salmon and is 258 times the level of cesium Japan’s government considers safe for consumption, Kyodo News reported.

The government banned shipments of fish from waters off Fukushima since May last year, with the exception of two types of octopus and one type of shellfish that have shown to be within cesium safety levels, said Noriyuki Mizobe, a group manager in the resources and environment research division of Japan’s Fisheries Agency.

Neighboring Ibaraki and Miyagi prefectures have introduced voluntary restrictions on certain fish shipments and radiation testing of catches. Other prefectures, including all bordering the Pacific coast, are testing fish catches for radiation, he said.

The Fukushima Dai-Ichi plant released massive amounts of radioactive substances into the air and the ocean after the March 11 quake and tsunami last year caused reactor meltdowns. Fishing and farming industries in the region north of Tokyo have been devastated as consumers shun produce from the areas because of radiation contamination fears.