Prague: An agency in the Czech Republic says about a half of all wild boars in the country's southwest are radioactive and considered unsafe for consumption due to the 1986 Chernobyl nuclear disaster.

The State Veterinary Administration said Tuesday that radioactive boars still roam the Sumava mountain range on the Czech border with Germany.

It says the animals remain contaminated nearly 31 years after the Chernobyl disaster because they feed on an underground mushroom that absorbs radioactivity from the soil. The nuclear reactor's explosion sent a radioactive cloud over Europe.

Cesium, the key radioactive material released, has a half-life of some 30 years. It can build up in the body, and high levels are thought to be a risk.

Similar problems with radioactive wild animals were reported in Austria and Germany.