In response a Monaco internet site says the American magazine are wrong, and have forgotten why Monaco's property prices are high in the first place.

'The error they made was comparing Monaco with places like Rome, Warsaw, Los Angeles and Vancouver, and they also overestimated closing costs. While admittedly high in Monaco at around 11 per cent, it's not common to be 20 per cent that their research was based on.'

The comparison of 50 financial centres assumed the property was not a main residence and looked at rental returns - another error when calculating Monaco's property prices according to the Monaco internet guide.

'By law in Monaco rentals are a minimum of one year, so it's obvious that rental returns are going to be less than places where weekly and six monthly rentals are possible. To gain residency in Monaco via renting the residency office needs evidence of a twelve month contract, so Monaco is in a unique position when compared to other leading financial centres.'

'There is a shortage of available property in Monaco and high demand that shows no sign of slowing down - given all these factors we just think the US magazine's analysis of the Monaco real estate scene has been done without taking local factors into consideration.'

Typical property prices in Monaco at the moment include a second floor studio apartment at 1,100,000 Euros, a one bedroom apartment in Monte Carlo at 2,150,000 Euros, and a three bedroom two bathroom apartment at 5,500,000 Euros.

As well as buying a property, to gain residency in Monaco a bank account needs to be opened in the Principality, with account opening deposits varying between 100,000 and 500,000 Euros.

One thing that could put the brake on the number of Brits looking to move to Monaco was announced after the magazine's claims about Monaco real estate prices were published.

The amount of time British tax exiles can spend in their home country is being limited by the British government, and it could impact the British economy, claim a company who specialise in tax haven property and residency.

Up until now a British taxpayer could avoid paying income tax by taking residency in a tax haven such as Andorra or Monaco, and be allowed to spend 90 days a year in Britain before falling foul of the Iland Revenue. Importantly both the day of arrival and departure into the UK didn't count as a day.

So technically, a tax exile living in Andorra could drive to Barcelona airport for a 7am flight to London, and given the hour's time difference between Spain and the UK, be comfortably in an office working by lunchtime.

Equally, the same tax exile could leave the London office at 6pm Friday for Barcelona en route to Andorra - and importantly those five days in the UK would count only as three of their ninety day allowance as the day travelling to and from the UK aren't counted. Which allowed business men and women to commute from the tax havens of Andorra and Monaco thirty weeks a year. Some would do Monday to Thursday and could do that virtually all year and still stay on the right side of the British tax man.