Anatoly Isaikin, the chief of Russia's state arms-trading monopoly, says Russia will step up action to defend the copyright of the Kalashnikov, which is made without licence by dozens of manufacturers around the world.

The Kalashnikov is the world's most widely distributed weapon, with 100 million made in the 60 years since the AK-47 went into serial production, but only about half are the genuine article.

The counterfeit production of AK-47s outside Russia has incurred financial losses, tarnished the brand because of poor quality and dented Russia's prestige abroad, Isaikin said.

Isaikin said his company, Rosoboron­export, was working to draft agreements with foreign countries that would protect copyright for Kalashnikovs and other Russian weapons. There are about 30 foreign manufacturers who are currently making Kalashnikovs, he said. "Together with other federal structures, we are taking steps to establish order," said Isaikin.

The Soviet Union paid little attention to copyright laws, handing out arms production licences to its satellites in eastern Europe and elsewhere. The Cold War-era production licences have long expired, but production has continued.

In 1997 the Izhmash factory in the Ural mountains city of Izhevsk, which makes Kalashnikovs, secured a state patent for the weapon and began pressing foreign manufacturers to respect its copyright.

Izhmash director Vladimir Grodetsky said the company has faced an uphill battle, losing an estimated $400m (¤266m) a year from counterfeit Kalashnikov makers. He said Venezuela, which has struck a deal to buy 100,000 rifles and produce more under licence, is now the only legitimate licence holder.

Other Kalashnikov makers, including eastern European nations and China, have signalled readiness to respect Russian copyright but have said the deals should be negotiated at government level, Grodetsky said.