A furtive friend to the powerful

The elusive Russian oligarch at the centre of a political row involving Peter Mandelson and Tory George Osborne will not welcome the attention the affair has brought

Who is he? Russia's richest man.

Why is he in the news? Top British politicians Peter Mandelson and George Osborne have been quizzed over time spent on his yacht.

Most appealing characteristic: Less flashy than your average oligarch.

Most annoying characteristic: Can't do without the regulation yacht: the 238ft Queen K.

Most likely to say: "Mr Putin, could I cadge a few billion to see me through this credit crunch?"

Least likely to say: "Of course you can come back on board, George. And bring a few friends from the British press this time."

ABOARD THE luxurious Queen K, as she drifted serenely off the coast of Corfu, it was surely hard for Peter Mandelson and George Osborne to imagine that such a lovely time could lead to such unpleasantness.

But the British business secretary and the Tory opposition's shadow chancellor have indeed come to rue their separate summer sojourns on the £80 million (€101 million) super-yacht, and been forced to fend off damaging allegations regarding their relationship with its mysterious owner.

He is Oleg Deripaska, a son of the Russian provinces who became an in-law and friend to Kremlin leaders; winner of his homeland's brutal "aluminium wars" of the 1990s and a trustee of Moscow's revered Bolshoi Theatre; a physics graduate and adviser to a department of Harvard University, who is barred from the United States and has been accused of having links to organised crime.

The man who Forbesnamed in April as the richest man in Russia is a man of contrasts, then, and he prefers to control his reputed $20 billion (€15.3 billion) fortune from well out of the public eye. Though rumoured to be sizing up several clubs, he has not bought an English football team like Roman Abramovich, nor strayed towards politics like Mikhail Khodorkovsky, the wealthiest man in Russia before he was thrown into a Siberian jail for fraud.

It must have come as a deeply unpleasant surprise to Deripaska to be splashed across Britain's newspapers in recent weeks, when his friend and business associate, Nathaniel Rothschild, accused Osborne of soliciting donations from the Russian while on board the Queen K.

And it cannot have felt any better to this lover of anonymity when the papers turned their spotlight on his relationship with Lord Mandelson, another guest on the 238ft yacht, and asked whether the former EU trade commissioner had in mind his generous host - and owner of the world's biggest aluminium producer - when he backed the bloc's decision to halve import tariffs on the metal.

All this unwelcome British scrutiny came shortly after the United States had pondered Deripaska's relationship with Republican presidential candidate John McCain, whom he reportedly met in Davos, Switzerland, and in the Adriatic state of Montenegro.

The tiny former Yugoslav republic plays a disproportionate role in Deripaska's story, and its limpid seas, sighing beneath soaring peaks and ancient walled ports, are regularly plied by the Queen K.

Wooed by beautiful scenery, cheap property prices, shared Slavic roots and a visa-free immigration policy, Russians have flooded into Montenegro in recent years.

While most come for a typical two-week package holiday, the wealthy often buy a villa or a plot of land, and the very rich buy a hotel, an apartment complex or a stretch of stunning coastline.

When Deripaska came to Montenegro, he ended up buying the aluminium smelter and bauxite (aluminium ore) mine that account for about half the country's entire exports, and now he is building - along with Rothschild and other partners - a luxury resort with berths for hundreds of yachts.

Not bad for a country boy who says he learned crucial lessons in responsibility by tending horses on his grandparents' farm in southern Russia, before moving with his mother to the nearby village of Ust-Labinsk, some 1,000km from Moscow.

It was at Moscow State University that Deripaska, born in 1968, earned a degree in physics and first learned the English that he has polished since making the acquaintance of the likes of Rothschild, Mandelson and Osborne, and since buying a £20 million house in London's Belgrave Square.

Like his upbringing, Deripaska's university years could hardly have been more different to those of his well-heeled English pals, Rothschild and Osborne, who lived it up as members of the University of Oxford's Bullingdon Club, where for centuries the young English elite has enjoyed drunken japes.

Deripaska has said he worked on building sites to make ends meet, as the Soviet Union collapsed and capitalism arrived with a huge and bewildering bang.

After leaving university, Deripaska set up his own small metal trading firm and began to make a name for himself as a young, talented and dynamic figure in a post-Soviet business world brimming with extreme risk and the possibility of extraordinary reward.

After Boris Yeltsin distributed vouchers to millions of workers to allow them to buy shares in newly privatised companies, many of them immediately sold these shares for a pittance to supplement wages that were at best meagre, and often were not paid at all.

According to Michael Cherney, a Russian businessman now living in Israel, he and Deripaska teamed up to buy a tranche of such shares in the Sayanogorsk aluminium smelter in Siberia.

They were involved in a business that was as dangerous as it was potentially lucrative, in which the Soviet Union's vast mines, smelters and factories, often in the most inhospitable corners of Moscow's vast empire, were suddenly up for grabs. This was a game in which there were no rules, few allegiances, and victory was often secured by any means necessary.

"The deaths were probably in the scores, as many as 40 or so when you take into account all the lower-profile guys," says James Fenkner, the manager of a Russian hedge fund who was an eye witness to what became known as Russia's "aluminium wars".

Fenkner worked in Moscow for a US commodities brokerage when its Russian metals chief was killed during the struggle for control of another Siberian aluminium smelter. "Certainly, it was not a clean business," he says.

Cherney says he left Russia for Israel in 1994, in fear of attack from organised crime groups, and made Deripaska the manager of the Sayanogorsk business, which became the core of a big metals group called Sibirsky Aluminium.

In 2000, Sibirsky was merged with aluminium assets belonging to Roman Abramovich's Sibneft oil company to create a world player called Russian Aluminium, or Rusal.

Abramovich sold his stake in the firm to Deripaska in 2003 and, after acquiring two major competitors, Rusal is now the biggest aluminium company in the world, and the main unit in Deripaska's sprawling holding company, Basic Element. There is an Irish link here. In 2006 Rusal acquired the Aughinish Alumina plant in Limerick, which employs 500 full-time staff and 200 contract workers, contributing about €100 million to the local economy each year.

Through Basic Element, Deripaska controls stakes in everything from aircraft builders to insurance brokers, construction firms to British van makers, as well as his various interests in Montenegro.

IT IS NOT ALL PLAIN SAILING for the master of Queen K, however. Cherney claims Deripaska owes him 20 per cent of Basic Element, and is trying to sue him in a London court to win his stake. Deripaska insists he does not owe Cherney a rouble, and wants the case to be heard in Russia.

A British judge found this summer, however, that Cherney could face a rigged trial and even assassination if he returned to his homeland to pursue the claim, in a ruling that Deripaska is appealing.

The judge's verdict casts further shadows on a reputation already darkened by a US refusal to grant Deripaska a visa, for reasons the Russian and the Americans have declined to reveal.

The businessman has always rejected suggestions of shady dealings and alleged links to underworld groups, and has accused business rivals of trying to sully his image.

And while foreign critics see his cultivation of people like Osborne, Mandelson and Rothschild as an attempt to bring a veneer of establishment respectability to his operations, at home Deripaska has long been part of the elite.

In 2001 he married Polina Yumasheva, the daughter of a top Yeltsin aide, who himself later married one of Yeltsin's daughters.

The weddings made Deripaska the husband of Yeltsin's grand-daughter by marriage, linking him to the coterie of people who flourished in and around Yeltsin's Kremlin, a group that Russians call simply "The Family".

Many of these figures were sidelined by Yeltsin's successor, Vladimir Putin, but Deripaska has thrived.

The key has been his loyalty to Putin and his willingness to put his business empire to work in the service of Russia: analysts say he reported personally to Putin on his operations in Montenegro, and he is poised to play a major role in building infrastructure for the 2014 Winter Olympics in the southern Russian city of Sochi, a project championed by Putin.

And when the recent credit crunch wiped billions of dollars off Deripaska's wealth and forced him to sell assets to cover debt repayments, Putin quickly offered state loans to see him and fellow oligarchs through the storm.

Mandelson and Osborne may demur, but the Kremlin's favourite oligarch clearly flourishes among friends who are as influential as his fortune.