Russian authorities from Sheremetyevo airport in Moscow have seized radioactive material from a passenger headed to Tehran, Iran.
According to CNN, agents found "18 metal objects packed in individual steel cases."
The objects had radiation levels 20 times higher than normal, and were later found to contain isotope Sodium-22.
A spokesperson for Russia's Federal Customs Service said that the isotope "can be obtained in a nuclear reactor."
Sergei Novikov, a representative from the Rosatom nuclear agency, however, told the Associated Press that the material is made by particle accelerators, not nuclear reactors.
Isotope Sodium-22 is used in nuclear medicine imaging equipment, and "universities, research institutes, and big medical centers have the technology to produce it," said Novikov.
Read more from GlobalPost: Japan: Radioactive rice found near Fukushima
Investigations into the incident and the passenger are continuing.
According to Al Jazeera, Russia has had close ties with Iran when it comes to nuclear power.
The country built its first nuclear power station in the south of Iran, known as the Bushehr Nuclear Power Plant.
Novikov told the AP that his nuclear agency never sold Sodium-22 to Iran, but "it has supplied it with other types of medical isotopes."
Read more form GlobalPost: No leak reported after deadly explosion at French nuclear site