Radioactive caesium was detected from two minke whales caught off a city on the northern Japanese island of Hokkaido, 650 kilometres north-east of a damaged nuclear plant, a news report said Tuesday.
Researchers examined six of the 17 whales during so-called research whaling in Kushiro city, which started this year's season in late April, and they detected 31 becquerels and 24.3 becquerels of radioactive caesium per kilogram in the two whales out of the six, Kyodo News reported citing a whalers' association said, DPA reported.
While the level of the radioactive substances remained below the limit of 500 becquerels per kilogram, the association officials told a news conference in the city that the contamination must have been caused by the ongoing crisis at the Fukushima Daiichi nuclear power plant, Kyodo reported.
Since the plant was damaged by a magnitude-9 earthquake and ensuing tsunami on March 11, it has leaked radioactive substances into the environment.
In 1987, Japan halted commercial whaling, complying with an international moratorium that went into effect in 1986. Japan, however, has used a loophole in the accord to continue whaling under the premise of conducting scientific research.