SYDNEY (AFP) - An Australian property mogul on Wednesday lost his lawsuit against the nation's largest casino after wagering more than US$1 billion (S$1.25 billion) there and losing over US$20 million.

High-roller Harry Kakavas sued Melbourne's Crown Casino to recoup his losses, alleging it lured him with gifts and private jet flights while knowing he was a compulsive gambler who had been barred from a casino in Sydney.

Mr Kakavas wagered US$1.43 billion over 16 months on baccarat at the Crown and accumulated net losses of US$20.5 million. He argued that the casino ought to repay him because it had exploited his "pathological urge to gamble".

But the High Court of Australia threw out his case.

"The court did not accept that the appellant's pathological interest in gambling was a special disadvantage which made him susceptible to exploitation by Crown," the judges said.

"He was able to make rational decisions in his own interests, including deciding from time to time to refrain from gambling altogether.

"Crown did not knowingly victimise the appellant by allowing him to gamble at its casino."

Mr Kakavas was described by the initial judge assessing his case as "the highest of this country's high-rollers" and a prolific gambler who had tried his luck in Las Vegas, Hong Kong, Macau and the Bahamas.

He had some spectacular wins at Crown, where he was allowed to bet single hands of up to US$300,000 before ultimately losing "all he won, and more", the lower court judge said.

Mr Kakavas was eventually banned from Crown after blowing more than US$2 million on the card tables in just 43 minutes in August 2006.