Said to have switched real euros for fakes in diamond and

Conmen scammed dealers out of diamonds, jewellery and watches worth over £500,000 using Monopoly money, a court heard.

Real euros were switched for bundles of fake facsimile notes or board game cash in three cons in London, Bristol and Leeds, a jury was today told.

Victims were allegedly tricked despite using a pen or a machine to count the bundles of cash when bands were used to cover the fake notes.

They only discovered they had been duped after transferring the valuables to the crooks, who had fled.

Conmen scammed dealers out of diamonds, jewellery and watches worth over £500,000 using Monopoly money, a court heard. Gianni Accamo, 44, is linked to all three scams, Bristol Crown Court heard

Accused fraudster Gianni Accamo, 44, is linked to all three scams, Bristol Crown Court heard.

David Hughes, prosecuting, said he was part of a gang that targeted Australian jewellery dealer John Calleija, who has a shop in the Royal Arcade in London's Old Bond Street.

Mr Calleija was told an investor had five million euros to buy diamonds and a gemologist - allegedly Accamo - went to inspect his stock of precious stones.

A deal was struck at a Convent Garden hotel where Mr Calleija and a bodyguard used his cash counting machine to count bundles of 500 euro notes, totalling 7.7million euros.

Mr Hughes told the court: 'When Mr Calleija finished counting the notes the machine didn't pick up a single problem.

'He turned to place his counting machine into its case. They leave the room.'

But Mr Hughes said that was when the real euros were switched for bundles of fake notes with 'facsimile' written on them, masked by paper bands on the outside.

The diamonds were collected from Mr Calleija's shop and it was only later he discovered he had been had, the court heard.

Mr Hughes said: 'You can imagine the horror when he goes to check the cash.

Real euros were switched for bundles of fake facsimile notes or board game cash (pictured) in three cons in London, Bristol and Leeds, a jury was today told

'It is immediately apparent it is not the same that he had counted in the hotel. It's counterfeit.

'At some point during that fatal turn around to put that cash counting machine away, the real money has been switched.

'The fake money has been substituted and the criminals had disappeared with the diamonds.'

Mr Hughes said Accamo was also linked to a £420,000 fraud in Bristol involving Wales-based jeweller Jack Cohen who had struck a deal to sell watches and diamonds.

Mr Cohen brought watches to a Bristol hotel but left his diamonds at David Edwards Jewellers in Cardiff.

At some point during that fatal turn around to put that cash counting machine away, the real money has been switched David Hughes, prosecuting

Mr Cohen was told he would be paid in euros and he used a testing pen to count bundles of 100 euro notes which appeared to be real, the court heard.

He put the cash in a bag and gave permission for the diamonds to be couriered to the buyers in August 2014.

Mr Hughes said: 'Mr Cohen leaves Bristol and goes to Cardiff. He's got fake euros saying Monopoly, with banding covering the word Monopoly.

'He immediately calls police. His loss is around £420,000.'

The court heard that Accamo, of no fixed address, was also linked to a £192,000 scam in Leeds.

It involved a man called Marvin Santos who lost nine expensive watches and a diamond linked gold chain to a con gang between September and November 2014.

Accamo denies conspiracy to commit fraud in August 2014 by making false representations in order to obtain watches and jewellery worth £420,000 in Bristol.

He also denies theft involving Mr Marvin Santos but has admitted conspiracy to commit fraud in the London scam.