While the £1 coin remains heavily faked, the £2 has remained almost untouched because of the difficulty criminals have connecting the inner and outer pieces of the coin together.

But a shipment of fake euro coins intercepted in Naples, Italy, three months ago, has revealed forgers are now producing bi-metallic coins in massive quantities.

The seizure - the largest of its kind in the history of the Euro - is likely to cause concern among British investigators given its ramifications for the £2 coin.

A British investigator told The Times counterfeiters had historically struggled to make convincing £2 coins.

He said: 'You've always been able to tell a fake by dropping it on a table - they rattle because the two bits have not been stuck together properly.'

'On arrival in Italy, the coins are distributed throughout Europe by other members of the criminal group, led by the main suspect in Palermo, who is a Ghanaian national.'

Twelve people were arrested this month after an investigation was launched following September's seizure.

Investigators said: 'From this first seizure, investigators realised that the criminal group had the capability to produce a vast quantity of good quality fake coins, as the criminals were using sophisticated manufacturing techniques, very similar to those used to produce authentic coins.' 

It was the largest such seizure in the history of the currency, and were so perfect they would work in vending machines across Europe.

Palermo prosecutor Calogero Ferrara said: 'They were high-quality fakes produced at a clandestine Chinese mint and ready to be put on the Italian market just before the Christmas spending rush.'

A spokesperson for The Royal Mint said a recent Britain-wide survey unearthed only one fake £2 coin and it worked closely with HM Treasury, the National Crime Agency and the cash-handling industry.

'Together we ensure that every effort is made to maximise opportunities to identify and withdraw counterfeit coins from circulation.'

(dailymail.co.uk)