Ukrainian authorities denied on Tuesday a report in pro-Kremlin media that a radioactive leak had taken place at the Zaporizhzhya nuclear plant, Europe's largest.
Life News newswire published documents which it said came from Ukraine's emergencies ministry and showed that a leak at the power plant had led to a spike in radiation over the past two days exceeding permitted norms by 16 times.
Three officials from Ukraine's emergencies ministry, energy ministry and the plant itself told Reuters there had been no leak.
"The plant works normally, there have been no accidents," said an energy ministry official. The officials could not comment if documents published by Life News were authentic. Reuters was not able to verify the documents independently.
Russia and Ukraine are going through one of the worst phases in relations after Moscow annexed Ukraine's Crimea peninsula and was accused by the West of sending troops to east Ukraine to support a rebellion against Kiev.
In the nuclear sphere, Moscow and Kiev are at odds over supplies on nuclear fuel after Ukraine said it wanted to replace some Russian supplies with fuel from U.S. firm Westinghouse. Moscow said the move would put the safety of Ukrainians and Europe in general in danger.
Earlier this month, Ukrainian authorities reported an accident at the plant but said it represented no danger to health or the environment.
An explosion and fire at Ukraine's Chernobyl power plant in 1986, the world's worst nuclear accident, was caused by human error and a series of blasts sent a cloud of radioactive dust billowing across northern and western Europe.
(By Pavel Polityuk; Writing by Dmitry Zhdannikov; Editing by Angus MacSwan)