Mike Ashley, the controversial Sports Direct founder and Newcastle United football club owner, faces a legal threat to his attempt to acquire Les Ambassadeurs, the London casino.

Although Mr Ashley’s estimated £95 million offer is believed to be the highest bid on the table, The Times understands that Las Vegas Sands, the American gaming behemoth, is claiming it had previously agreed a deal at about £75 million.

Sheldon Adelson, the head of Las Vegas Sands and one of the world’s richest men, with an estimated fortune of £13 billion, is understood to be threatening to sue the casino’s Indonesian owners if they attempt to sell it to another bidder.

Mr Adelson is also believed to have contacted rival bidders through his lawyers, Mishcon de Reya, claiming he has a binding verbal agreement to buy Les Ambassadeurs and threatening legal action against them if they attempt to gazump him.

Les Ambassadeurs is one of the world’s plushest casinos, numbering high-rollers including Sir Philip Green, the Bhs and Top Shop billionaire, among its members. Sir Philip is a close friend of Mr Ashley but has denied any involvement in the bidding for the club.

The handsome Georgian building that houses “Les A”, as it is known, has a rich history, having previously been the residence of assorted nobles and aristocrats, including Leopold de Rothschild, the City banker, who moved there in 1879.

The current owner, Putera Sampoerna, acquired it almost two years ago from London Clubs International (LCI) for £115 million. The Indonesian entrepreneur is reputed to be worth about £1.2 billion after selling his family’s clove cigarette business to Altria, the US tobacco group formerly known as Philip Morris, for $5.2 billion (£2.55 billion) a year earlier.

Observers have expressed surprise that Mr Sampoerna should consider selling the club at a loss, although some believe he may have become disenchanted with its performance in the wake of the recent rise in gaming duty and the smoking ban. The watering down of gambling deregulation was also cited as a possible factor.

Analysts believe the threat of legal action from one of the world’s most formidable businessmen may cause the Sampoerna family to put the sale of Les A on hold. One City source suggested that Mr Ashley may already have lost interest in buying it.

In the early stages of the sale process analysts were tipping Harrah’s Entertainment, another Las Vegas gaming giant and the owner of LCI, the casino’s former owner.

However, Harrah’s is itself the subject of a recommended $27.8 billion takeover by Apollo Management and TPG Capital, and the buyout firms are said to have vetoed a purchase of Les A in the light of tough trading conditions in the UK.

Las Vegas Sands is believed to view Les A as a strong brand that could be rolled out as part of Mr Adelson’s ambitious expansion plans. In addition to the Venetian Resort Hotel Casino and the Sands Expo and Convention Center in Las Vegas, it runs the Venetian Macao Resort Hotel and the Sands Macao.

It is developing three further resorts in Las Vegas, Pennsylvania and Singapore as well as the Cotai Strip in Macao.

Las Vegas Sands declined to make any comment, while neither Mr Ashley nor Mr Sampoerna could be reached for comment.

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive