The environmental charity, Greenpeace, has said the health effects of the Chernobyl nuclear disaster in Ukraine 20 years ago have been grossly underestimated.
Official figures from the United Nations have predicted 4,000 extra cancer deaths caused by the radioactive fall-out from Chernobyl.
In a report released today, Greenpeace says recent studies estimate there will be many more deaths in Ukraine, Belarus and Russia.
A Greepeace spokesman also said non-cancer deaths needed to be taken into account.
