Wolves from the Chernobyl site have been roaming freely beyond the nuclear disaster zone’s border, increasing fears that they will spread mutant genes.
The site became off limits to humans after the nuclear power plant disaster on 26 April 1986, due to concerns about the level of radiation, although it has opened to tourism in recent years.
But it is thought that the lack of human interference has allowed animals to thrive in the 18.6-mile-wide exclusion zone.
Wolves began to take over the site in 2016, when their population was thought to be around 300.
Scientists have followed the wolves as the population has grown to a number now estimated to be up to seven times greater than that of surrounding reserves.
Fourteen grey wolves (13 adults and one male juvenile) were tracked using GPS collars to see how far they strayed from the exclusion zone.
Study lead author and wildlife ecologist Michael Byrne told Live Science: “No wolves there were glowing – they all have four legs, two eyes and one tail.”
In their article for the European Journal of Wildlife Research, the researchers said that the adult wolves had stayed in the zone but within three weeks, the young wolf had been tracked roaming around 186 miles away.
This raised questions as to the effect of wolves potentially affected by damaging radiation carrying mutant genes to pass onto other wolf communities.
Mr Byrne said: “We have no evidence to support that this is happening.
“It is an interesting area of future research, but it is not something I would worry about.”
The Chernobyl nuclear disaster saw the power plant release about 400 times more radioactive fallout than the bomb dropped on Hiroshima near the end of World War Two.
Particles were spread thousands of miles across Europe, dozens of residents were killed and many others exposed to the radiation.
Mr Byrne told Live Science: “Instead of being an ecological black hole, the Chernobyl exclusion zone might actually act as a source of wildlife to help other populations in the region.
“And these findings might not just apply to wolves – it’s reasonable to assume similar things are happening with other animals as well.”