Slovak and Hungarian police seized a kilo of radioactive material and arrested three people in a joint operation on Wednesday, a spokesman said.
Slovak police spokesman Martin Korch said the material was being examined and did not confirm a report carried by the Slovak news agency SITA that it was enriched uranium.
"This one kilogramme should have been sold for $1 million US dollars," spokesman Martin Korch said. The spokesman said the police raid took place along the eastern part of the two central European countries' common frontier, near their borders with Ukraine.
"Three people have been taken into custody, two in Slovakia one in Hungary," he said. "Further information will be provided tomorrow."
Uranium enrichment can yield either fuel for nuclear power stations, or be used for nuclear warheads.
