A man who gambled away almost $1.5 billion in 14 months at Melbourne's Crown Casino has begun his fight in Australia's highest court to win back a small fraction of his losses.

Gold Coast businessman Harry Kakavas, described in the High Court on Thursday as Australia's "highest of high rollers", claims Crown knew he was a pathological gambler but lured him back anyway to take advantage of his "special disability".

'Highest of high rollers': Harry Kakavas says Crown Casino knew he was a pathological gambler but continued to let him gamble away millions. Credit:Erin Jonasson

The court heard that between June 2005 and August 2006, Mr Kakavas spent $1.479 billion at Crown, winning and losing vast sums, often on hands of baccarat that took just seconds to play.

During one "frenetic" stint in May 2006, Mr Kakavas spent a staggering $164 million in just five and a half hours.