Russian investigators arrested a man in northwest Russia on Thursday for arms offences, including possession of an anti-tank rifle, the police said on Friday.

Police raided the man's apartment and country house in Gatchina, Leningrad Region, and uncovered an arsenal of weapons including the anti-tank rifle, pistols, grenades, mortar, and aircraft machine-guns, city police said.

The unemployed 39-year-old man was detained after he tried to sell a TT-30 semi-automatic pistol via the Internet and send it to the buyer by parcel post.

“Five pistols were discovered (a Mauser, Browning, Walther, and a Nagant) and an imported revolver; two Česká zbrojovka submachine guns; an IZH-8165 pump-action shotgun; an IZH-57 hunting rifle; a two-meter-long PTRD-45 anti-tank rifle; a mortar of German manufacture; and an aircraft gun,” the police said.

Two hundred rounds of ammunition were also found, as well as 17 grenades, five kilograms of TNT explosive, and many weapon components.

The PTRD-45, used during World War II, has an effective range of 800 meters against armored vehicles and 1,500 meters against soft targets.

A criminal case has been launched into “illegal possession, manufacturing, and sales of firearms and ammunition,” which carries a maximum punishment of three years imprisonment.