Bruno Venturi, 41, kept winning while playing a lottery-style game on Eurobet.com back in 2009.
However, the company which operated the gambling website insists a software bug meant chance had nothing to do with it.
Surrey-based Eurobet UK Ltd claims that his winnings are null and void because he was mistakenly charged for only one in six of his bets.
The company has refused to pay up, sparking a High Court legal battle, which Judge Simon Brown QC said reminded him of the 1935 film, ‘The Man who Broke the Bank at Monte Carlo’.
The film, inspired by a British music hall song of the same name, is a romantic comedy which tells the story of a former Russian aristocrat who by luck wins 10 million francs playing baccarat at a casino.
The casino dispatches a beautiful woman to attempt to lure him back to the gambling tables and he is eventually left penniless again.
Pet shop worker Mr. Venturi, who had won only meagre sums in his previous two years using the website, says he was completely unaware of what was about to unfold when he logged on to play the “Sixty Seconds” game from his home in Naples, Italy, on January 28, 2009.
The company claims an error caused by a software upgrade meant Mr. Venturi was charged for only one in six of the 6,670 wagers he placed, dramatically increasing his chances of winning the game, which has since been removed from the internet.
Patrick Lawrence QC, for Eurobet, said the bug meant it was “mathematically inevitable” that Mr. Venturi would keep hitting the jackpot.
The High Court in London heard that the Italian, who started with just 25 Dollars in his account, began playing at 8.18 p.m. by placing his usual 20 cent bets, but increased the stakes as his apparent luck continued.
He had won $6,275 by 9pm and racked up winnings of $250,000 by 10pm, as he frantically placed as many multiple wagers as the website would allow.
Speaking through an interpreter, Mr. Venturi told the court: “I had always lost previously… but when I started to win, I had a very good feeling. I’m a player and my instincts told me to keep betting.”
Mr. Lawrence challenged him, saying he must have realized that something was wrong, but Mr. Venturi insisted: “How could I realize there was an error. There was no message, I was just drawing, I didn’t have a clue… I thought I was very lucky.”
The Italian, who disputes that any error took place, stopped playing shortly before midnight, having amassed a colossal $888,190 – in just 217 minutes.
When asked why he called it a day, Mr. Venturi replied: “I realized the amount that I was winning and I realized that I had to stop. I had been lucky enough… I am only human. I was taken by the emotions and there was a lot of euphoria.”
He added: “I’ve never had so much money… It’s a very big win; it’s not something that happens every day.”
Mr. Venturi, who offered to come to England to pick up his winnings in cash, said an operator told him “This is incredible, but it does happen” as he transferred some of his winnings to a different online account.
The company, based in Working, is refusing to pay Mr. Venturi, saying the bets breached the website’s terms and conditions, and his winnings amounted to “unjust enrichment”.
Refuting those claims, Mr. Venturi’s barrister, John McLendon QC, said: “Mr. Venturi denies any software error as alleged by the defendant.
“The defendant has failed to establish that Mr. Venturi broke any rules of the game whilst playing and obtaining the winnings.”
He added: “Mr. Venturi performed his part of the game by completing various steps and screens presented to him by the defendant on the website and paid for his bets on the game from the funds in his account. He did everything that was required of him to pay for the bets.
“If his account was not charged at any time for the repeat bets, which is not admitted, that omission was due to the defendant’s failure to completely perform its obligations to him, and to comply with its regulatory requirements.”
The hearing continues.