Russian leader Vladimir Putin has made an astonishing bid to grab a vast chunk of the Arctic, giving himself claim to its vast potential oil, gas and mineral wealth.

His audacious argument that an underwater Russian ridge is linked to the North Pole is likely to lead to an international outcry.

Some commentators have already observed it is further evidence of growing Russian assertiveness under its authoritarian president.

The Russian media trumpeted the findings of a Moscow scientific mission to the region which boasts "sensational" geological discoveries enabling the Kremlin to make the territorial claim.

Populist newspaper Komsomolskaya Pravda - a cheerleader for Putin - printed a map of the North Pole showing a "new addition" to Russia, a triangle five times the size of Britain with twice as much oil as Saudi Arabia.

The six-week mission on a nuclear ice-breaker claimed that the underwater Lomonsov ridge is geologically linked to the Siberian continental platform - and similar in structure.

The detailed findings are likely to be put to the United Nations in a bid to bring it under the Kremlin noose, and provide the bonanza of an estimated 10 billion tonnes of gas and oil deposits as well as significant sources of diamonds, gold, tin, manganese, nickel, lead and platinum.

Under current international law, the countries ringing the Arctic - Russia, Canada, the US, Norway, Denmark (Greenland) - are limited to a 200 mile economic zone around their coastlines.

Currently, a UN convention stipulates that none of these countries can claim jurisdiction of the Arctic seabed because the geological structure does not match that of the surrounding continental shelves.

The region is administered by the International Seabed Authority - the authority now being challenged by Moscow.

A previous attempt to claim the oil and gas resources beyond its 200 miles zone five years ago was rejected - but this time Moscow intends to make a far more serious submission to the U.N. Commission on the Limits of the Continental Shelf.

The head of the government-funded expedition Valery Kaminsky, director of the All-Russian Oceanic Scientific Research Institute, said he has key photographic evidence to prove the geological claims. "These are very interesting facts for the world community," he said.

Yuri Deryabin, head of the Institute of North European Countries, said: "I estimate Russia's chances to gets its piece of the Arctic pie highly enough - but the main battle is just starting." He acknowledged the negotiations would be "complicated".

The claim is likely to provoke an outcry from green groups but there is also Russian opposition.

Sergei Priamikov, of Russia's Arctic and Antarctic Research Institute, said the notion was "strange" and warned other countries could make counter claims.

Canada "could say that the Lomonosov ridge is part of the Canadian shelf, which means Russia should in fact belong to Canada, together with the whole of Eurasia", he observed drily.

A diplomatic source said that Russia was "seeking to secure its grip on oil and gas supplies for decades to come. Putin wants a strong Russia, and Western dependence for oil and gas supplies is a key part of his strategy. He no longer cares if his strategy upsets the West".