The Okada restaurant at the Wynn casino in Las Vegas is renowned as one of the finest dining establishments in a city fast becoming the culinary capital of the US. Its website boasts that the menu, which includes the Rainbow Roll (snow crab, cucumber, avocado and assorted sashimi) and Beef Tenderloin Robatayaki (cipollini onions and yakitori sauce), represents “Japanese cuisine elevated to an art form”.

How much longer the restaurant will trade under the Okada name is unclear, after a week that has laid bare simmering tensions between Steve Wynn, the casino magnate who founded Wynn Resorts, and Kazuo Okada, the Japanese billionaire who invested alongside him.

Wynn Resorts, which operates casinos in Las Vegas and Macao, has accused Mr Okada, who until this week owned a 20 per cent stake in the company, of giving bribes to international gaming regulators. The group has seized his stake, for which it will pay Mr Okada $1.9bn in 10 years, representing a 30 per cent discount to its market value. The action followed an independent report by Louis Freeh, a former director of the Federal Bureau of Investigation, which made the corruption allegations against Mr Okada. The claims were the subject of a court filing by the company in the Nevada district court on Tuesday.

Mr Okada has denied breaking any laws. A representative said this week that the accusations levelled against him were “motivated by self-interest and represent the results of an incomplete and otherwise flawed corporate governance process”.

The US Securities and Exchange Commission is investigating the bribery and corruption allegations. It has also launched a probe into allegations Mr Okada has made in a lawsuit against the company about a $135m donation by a Wynn subsidiary to a university in Macao. He is seeking to block the seizure of his stake by applying for a temporary injunction.

On Friday Wynn Macau, the group’s Hong Kong listed subsidiary, removed Mr Okada from its board.

The unfolding saga and the tensions between Mr Wynn and the man of whom he once said, “I love Kazuo Okada as much as any man that I’ve ever met in my life”, underscore the shift in the industry’s centre of gravity from Las Vegas to Asia. Led by Macao, the former Portuguese colony near Hong Kong, a new and highly lucrative frontier has opened in that continent for US companies such as Wynn and Las Vegas Sands.

Asian casinos are in line to generate total revenues of $58bn this year, according to estimates by PwC, the consultancy. Most of that will come from Macao, where revenues have soared by more than 30 per cent a year and are forecast to reach $44bn in 2012 – far outstripping Las Vegas, where gaming spending has slid to about $6bn since the financial crisis.

Casinos in Singapore, which is not exactly known for excess and extravagance, are on the verge of overtaking Las Vegas and are estimated to have pulled in about $6bn in revenue in 2011 just two years after they opened. This has boosted the coffers of Las Vegas Sands, the only US operator with a casino in that country, and further enriched Sheldon Adelson, its billionaire chief executive, who is bankrolling the super-political action committee supporting Newt Gingrich’s campaign for the Republican presidential nomination.

Mr Adelson and Mr Wynn have led the Asian expansion by Las Vegas groups. They were once bitter rivals, with Mr Wynn, who prides himself on his luxury properties, accusing Mr Adelson of running a “Walmart-style operation”. Their spat was played out in the pages of Las Vegas newspapers, yet the two have since patched things up, according to people close to them.

They remain outsize personalities in an industry not lacking in colourful characters. Mr Adelson, who has a net worth of about $25bn, told Forbes magazine recently that he “might give $10m or $100m” to ensure Mr Gingrich wins the Republican nomination. Mr Wynn has appeared in television commercials for his Las Vegas Encore property apparently sitting on the edge of its roof some 48 floors up. He was friendly with the singers Michael Jackson and Frank Sinatra – he named one of his restaurants Sinatra at Encore in honour of the star – and once put an elbow through Le Rêve, the Picasso painting he was due to sell for $131m (the picture was repaired but the sale was cancelled).

He is revered in the gaming industry for ushering in the era of the vast resort casino and his meticulous attention to detail. He opened the first 3,000-room hotel in Las Vegas (The Mirage) and turned the nearby Bellagio into a must-see attraction thanks to its dancing fountains, which shoot jets of water into the air in time to classical and pop favourites.

“He concentrates on achieving excellence and is fastidious in his approach,” says Warwick Bartlett, chief executive of Global Gaming and Betting Consultants, an Isle of Man-based adviser on the industry. “He put a Ferrari showroom in the Wynn [hotel] in Las Vegas and no one thought it would work, but it now sells more Ferraris than anywhere else ... he’s a pathfinder.”

Mr Okada is a different kind of pathfinder, having made his fortune in Japan making pachinko machines. Pachinko, a hybrid arcade-style gambling game, is a popular pastime in Japan that nonetheless occupies a legal grey zone. Playing is lawful – flashy parlours can be found near any rail station or shopping arcade – but collecting money after a successful game is a violation of anti-gambling statutes. To get around these, parlours hand out token prizes that players trade for cash in back-alley kiosks – a fig leaf that has kept police and politicians looking the other way.

Pachinko is certainly lucrative but Mr Okada has of late had his eye on richer pickings: developing a casino in the Philippines. Less than a month ago, he was looking triumphant at the groundbreaking ceremony for his $2bn Manila Bay Resorts project – the first casino the 69-year-old has built on his own.

But his dream of turning his Aruze group into a global casino operator is at risk after Wynn Resorts accused him of infringing the US Foreign Corrupt Practices Act by hosting Filipino gaming regulators in $6,000-a-night suites and plying them with gifts and expensive meals. The report prepared by Freeh, Sporkin and Sullivan, the law firm run by Mr Freeh, alleges that the wife of one regulator received a Chanel bag.

In the report, Wynn Resorts board members allege that Mr Okada spoke of needing to “follow the local culture” by giving gifts to government officials. The law firm interviewed all members of the Wynn Resorts board who were present at a meeting in February 2011. The report alleges that one board member “recalled Mr Okada stating that conducting business in the Philippines was all a matter of ‘hiring the right people’ to pay other people”, while another director remembered him “being ‘adamant’ during the FCPA discussion that it is not corrupt to give ‘gifts’ ”.

“This report is in the heartland of the kind of allegations that have caused the [US] Department of Justice and the SEC to launch investigations,” says David Schindler at Latham & Watkins, another law firm.

The rift between Mr Wynn and Mr Okada, who both declined requests by the Financial Times for comment, highlights the cultural risks that surround the expansion by western groups into countries where bribes to officials and regulators may be more socially accepted. “I’ve been involved in dozens of cases in Asia where people say that in order to do business in these jurisdictions you have to pay bribes,” says Mr Schindler.

The danger for casino operators is that by adhering to anti-bribery laws from their home countries, they risk falling behind competitors in a region that is the world’s fastest-growing gaming market. “Companies from the US and UK, which have rigid bribery laws, risk being locked out of deals in Asia,” says Mr Bartlett.

Yet students of Las Vegas history know US casino gaming has long suffered from its own problems with corruption and bribery. Organised crime got its hooks into Las Vegas the moment the gangster Bugsy Siegel drove there from Los Angeles in 1942 and decided the dusty desert town had potential as a tourist destination. Over the next three decades a succession of Mafia-related interests controlled several casinos in Las Vegas, their ownership often concealed from the authorities.

When Mr Wynn visited as a boy in the 1950s, many of the city’s casinos were under the influence of organised crime. But by the late 1970s – the time of his ascendancy in Las Vegas – Wall Street firms and institutional money had replaced the Mob.

Junk bonds financed Mr Wynn’s plans and a new generation of resort casinos was born: vast gaming palaces such as The Mirage and Bellagio, with thousands of rooms, luxury restaurants and top-class entertainment.

As destinations including Taiwan, South Korea, Japan and even Sri Lanka consider opening their gaming markets and offering casino licences, Mr Wynn and his rivals are waiting to pounce. But like every good gambler they will be aware that, besides the enticing rewards to play for, different cultural perceptions mean there are also significant risks.

Additional reporting by Roger Blitz in London and Jonathan Soble in Tokyo

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