Three men were caught with five kilograms of “regulated and prescribed material” Uranium-238 on the city’s outskirts Tuesday. They are suspected to have got the radioactive material, also known as depleted uranium, from an imported scrap consignment belonging to a Navi Mumbai company.

They were arrested and booked under sections of the Atomic Energy Act by the Panvel police. Nuclear experts say that Uranium 238 is a “protected material” with only special and regulated agencies allowed to possess and transport it.

Premsingh Tangayan Savitri of Sai Nagar in Panvel, Venkat Dalapathi of Vashi and Tulsidas Bhanushali of Ghatkopar were produced in the Panvel court and remanded in police custody till December 17. They been charged under Section 24 (1)(a) of the Atomic Energy Act, 1962, which lists the offences for prohibition of acquisition, production, and possession of Central Government prescribed material.

Maharashtra Police sources said they suspect the watchman of a Navi Mumbai company pilfered the uranium and sold it to Bhanushali who probably passed it on to Savitri and Dalapathi. The arrested men are suspected to be “mediators” in a deal with a third party. The police are yet to find the watchman and establish the identity of the possible buyer, the sources conceded.