A celebrity jeweller of Maltese descent was tricked out of €7.7 million by a gang of conmen who switched real cash for Monopoly money.

Mr Calleija. Photo: www.calleija.com.au

John Calleija, born in Australia to Maltese and Italian parents, was lured to London's Covent Garden Hotel by an "investor" who visited his jewelry shop on Old Bond Street. 

There, gang leader Gianni Accamo struck a deal with Mr Calleija to buy €7.7 million in diamonds, paid in wads of €500 notes. 

But when Mr Calleija and his bodyguard turned their backs, Mr Accamo and his accomplices switched the cash for bundles of toy money which had 'facsimile' printed on them. 

Although Mr Calleija was the gang's biggest mark, he was by no means their only one. A court in Bristol heard that the group had run similar scams in Bristol, Leeds and Wiltshire, the Lincolnshire Echo reported.

In each case, the gang would sandwich Monopoly notes in between real money to throw buyers off. 

Mr Accamo and his four accomplices were jailed for a total of 22 years for the scam. 

Mr Calleija is a renowned jeweller with shops in Mayfair and Sydney's Martin Place. His diamond jewelry has won multiple awards and he counts celebrities Zara Phillips and Colin Firth among his clients. 

According to his website, he took his first steps in the jewellery trade after becoming the apprentice to a Maltese jeweller.