All manner of products can be bought online, but one would never expect to find nuclear substances.

And then it happened.

Radioactive material, likely uranium, was sold through an Internet auction in Japan, investigative sources said Jan. 31.

The Metropolitan Police Department in Tokyo has already identified the seller and buyers, with the perpetrators suspected of violating the law regulating nuclear source material, nuclear fuel material and reactors, which prohibits non-authorized individuals from handling nuclear substances.

According to sources, the secretariat of the Nuclear Regulation Authority received information from an outside party at the end of November 2017 that “99.9% Uranium” was being sold on a Web auction site in Japan.

The secretariat reported the matter to police in January 2018.

After Tokyo police identified the seller and buyers, all male, it confiscated the substance last summer after obtaining a warrant.

The confiscated substance, in powder and solid form, was kept in several glass vessels. The total stash weighed several grams and emitted a small amount of radiation.

The seller was quoted by police as saying that the substance is “depleted uranium” and that he “bought it on a foreign website.”

In mid-December 2018, police asked the Japan Atomic Energy Agency in Tokai, Ibaraki Prefecture, to analyze the substance and expects to receive results of the analysis soon.

Police said the substance is possibly “depleted uranium” or “uranium concentrate" (yellow cake). The latter is made by refining uranium ore.

Uranium in natural form is used as nuclear fuel for nuclear weapons and nuclear power plants. However, enrichment can increase the ratio of uranium-235, which easily undergoes nuclear fission.

During this process, depleted uranium is generated, which has a low rate of uranium-235.