China said on Tuesday it had no knowledge of a report that two ethnic Koreans were arrested in the country for attempting to sell enriched uranium that could be used to make a nuclear bomb.
South Korea's largest circulation daily, Chosun Ilbo, reported on Tuesday that Chinese police arrested the pair in September at a Beijing hotel for trying to sell about 970 grams (34 ounces) of enriched uranium.
"I have tried to consult with relevant authorities, but I haven't received any information yet," Chinese foreign ministry spokesman Liu Jianchao told a regular press conference.
"But China's position on the control of sensitive items is quite clear -- we do not allow people to bring in sensitive items, especially radioactive items.
"China's police will take necessary action according to Chinese law."
The South Korea news report quoted a Beijing police source as saying the enriched uranium "was presumed to be Russian-made", but it could also have come from North Korea.
The report did not say how enriched the uranium was, but only highly enriched uranium can be used to make a nuclear weapon.
Fifteen to 17 kilograms of enriched uranium would be needed to produce a nuclear bomb, the newspaper said.
The United States accused North Korea in 2002 of running a clandestine nuclear program based on enriched uranium. The North declared on October 9 it had tested a nuclear weapon for the first time.