Crises at home and turmoil on world markets may have taken the shine off London's luxury property market for Chinese, Russian and Middle Eastern investors: some are even looking to sell up.

From Russian oligarchs and Middle Eastern oil barons to newly-minted Chinese entrepreneurs, foreign buyers have driven a spending spree on London property over the past two decades, snapping up everything from opulent homes to iconic commercial property.

London is not alone. Wealthy overseas buyers have been investing in other cosmopolitan cities such as Sydney and New York, where property purchases are also viewed as a prestigious insurance policy against changes of fortune.

But oil has lost nearly two thirds of its value since mid 2014, the Russian rouble has more than halved and Chinese growth is slowing. The scale of this wealth destruction combined with property tax rises in London has prompted investors to pause, estate agents said.

"There's definitely been less (interest) ... over the last six months or so with the oil price and currency issues for the Russians," said Ed Mead, executive director of Douglas & Gordon estate agents which sells some of London's most expensive homes.

"If people have bought a property here, which a lot of Chinese people have done over the last few years, we are definitely seeing more of them coming to us, saying look can you sell it for me."

Data from estate agents and property consultancies shows there has been a fall in transactions in some of the most expensive areas of central London, a decline in asking prices and fewer Russian, Chinese and Middle Eastern buyers.

Around 4 percent of prime London property buyers were Chinese in the first half of 2015 but that fell to 3 percent during the second half, according to data from property firm Savills.

London ranks as the best city in the world for the global ultra-rich taking into account factors such as quality of life, business and leisure, according to the consultancy arm of estate agent Knight Frank, followed by New York, Hong Kong, Singapore and Shanghai.

MOSCOW-ON-THAMES

There was an even sharper fall in the number of Middle Eastern and North African buyers in 2015, with the proportion of those purchasing homes in central London's most expensive area more than halving to 4 percent from 10 percent in 2014.

"People like the Qataris ... a year ago were big buyers and sovereign wealth funds too in London," said Charlie Ellingworth, who co-founded firm Property Vision which helps top-end buyers find homes worth more than 1 million pounds.

"By all accounts that's going into reverse."

The oil price has fallen by almost 60 percent since late 2014, hitting its lowest since 2003 in January, as near-record levels of output have caused currency devaluations and pushed Saudi Arabia to a record budget deficit.

"When you've got an environment like this: the oil price has gone through the floor, the stock market is falling all over the place, everyone just sits like a frozen rabbit," Ellingworth said.

London was once dubbed 'Londongrad' or 'Moscow-on-Thames' as the city of choice for rich Russians and other residents of former Soviet republics but enquiries from Russians fell 60 percent year-on-year in 2015, he said.

In prime central London, the number of transactions fell by nearly a fifth in the last six months of 2015 compared to the same period in 2014, according to Knight Frank, with asking prices often needing to decline by 10 percent or more.

Prices fell in some of the most attractive postcodes to foreign buyers including Knightsbridge, home to department store Harrods, Notting Hill and Chelsea.

TAX PLEASE

As London has traditionally benefited from far-off crises, some estate agents said the pause in buying from Russia, China and the Middle East was also being driven by a rise in UK taxation.

In an attempt to allay the anger of locals priced out of the British capital, finance minister George Osborne has increased the taxation foreign buyers have to pay.

Osborne has raised the amount of a property levy known as stamp duty paid on homes worth more than just under a million pounds, hiked the tax on properties bought through a company structure and cut mortgage interest relief for landlords.

"There has been (a decline) but that is probably as much to do with what George Osborne has done as with what the Russians have done themselves," said Charles McDowell, an agent who mainly helps buyers find properties in some of the capital's most desirable areas.

Multi-million pound properties are regularly sold in London with a seven-bedroom home with six bathrooms, a jacuzzi, sauna, cinema and two terraces currently on the market for 55 million pounds ($80 million) in Belgravia, one of the most expensive parts of Europe.

Jonathan Hewlett, head of London sales at Savills, said that in the long term the capital still had a well-established reputation worldwide as a place to invest.

"I think when you talk to people from overseas, they still see London as a very safe, nice place to live, safe for security, safe for ownership of property,” he said.