A high-rolling gambling addict has lost his High Court bid to sue Melbourne's Crown Casino for losses of $20 million.

Gold Coast property developer Harry Kakavas accused the casino of unconscionable conduct after it allowed him to gamble millions of dollars when staff at the casino knew he had a gambling addiction.

Between 2005 and 2006 Mr Kakavas turned over $1.4 billion at the casino when the losses were made.

Mr Kakavas was once jailed for fraud in relation to gambling and was on an interstate ban.

He alleges Crown staff lured him to their casino with incentives including the use of a private jet.

But the High Court said it did not accept his pathological interest in gambling was a special disadvantage, making him more susceptible to exploitation from Crown, and that Crown had not knowingly victimised him.

The casino argued Mr Kakavas had not indicated anything other than he was financially capable of maintaining his high-roller status.

In 2009 the Victorian Supreme Court heard from lawyers for Crown that Mr Kakavas was banned from the complex in 1998 for unruly behaviour, but he continued to threaten the casino with legal action if they did not allow him to return.

The court heard at the time that it was the property developer who initially requested but was denied the use of the private jet.