Children living near the Fukushima nuclear meltdown site have been diagnosed with thyroid cancer at a rate of up to 50 times that of children elsewhere, according to a new study.
Its authors claim it undermines the government's argument that more cases have been discovered in the area only because of more stringent monitoring.
Most of the 370,000 children in Fukushima prefecture have been given ultrasound check-ups since the March 2011 meltdown at the tsunami-stricken Fukushima Dai-ichi nuclear plant.
The most recent statistics show that thyroid cancer is suspected or confirmed in 137 of those children - a 25 per cent increase on the year before.
Elsewhere, the disease only occurs in an estimated one or two out of every million children per year.