Has lucky No17 cost high-rolling soccer boss £5million?

Mike Ashley, the billionaire owner of Newcastle United, is the man who walked away from a casino earlier this year with £1.3million, won on the single spin of a roulette wheel with his lucky number 17.

But if claims circulating among London’s big spenders are to be believed, Mr Ashley’s winning streak is finally over.

He is said to have recently lost £5million playing roulette and blackjack in one all-night session.

‘Lady Luck can be fickle,’ said a source, ‘but this was something else. Mike had been on a winning streak but it all unravelled on one long night. He even had breakfast at the club.’

Night to forget: Mike Ashley

The 45-year-old tycoon, who banked £929million when he floated his Sports Direct retail chain in February last year, is said to have run up the vast loss with friends at the casino Fifty, in St James Street, Mayfair, the same club where he won big in May this year.

At one stage the friends are believed to have tried to convince Mr Ashley to cut his losses as number 17 failed him time after time, but he ‘ploughed on regardless’.

A source at the casino said: ‘He normally takes his losses well, but by the end he had a face like thunder.’

Notoriously shy, Mr Ashley, whose current empire includes the leading sports brands Dunlop Slazenger, Donnay, Kangol and Lonsdale, was once described as ‘Britain’s answer to Howard Hughes’.

But he is regularly seen at Newcastle United matches when he wears a replica shirt bearing the number 17.

Last night Mr Ashley sat among Newcastle supporters wearing a club shirt as he watched his team play Arsenal at the Emirates Stadium.

He was picked out by the TV cameras apparently downing a pint of lager in one.

He bought the club last year for £135million, but admitted last month that he was looking for a partner.

He denied rumours he was looking to offload the club outright, but said he would be interested in selling some of his stake to local businessmen.

The maverick businessman has been dogged by rumours of penny-pinching since he took over. In June it was reported he had ordered its millionaire footballers to buy their own club suits.

Other famous gamblers who have taken big hits include the late Australian billionaire Kerry Packer who ended up £6million down at a Las Vegas casino in 1993. And Syrian-born Fouad al-Zayat, known as the ‘Fat Man’, lost £2million in 2000 at Aspinall’s Club in Mayfair.