Asian and Russian homebuyers who once made up a third of those buying property in London's wealthiest areas have largely deserted the market this year as emerging market currencies plunged against .
Properties in leafy boroughs such as Kensington, where the average home price is £1.5m, have been a sought-after asset in recent years among wealthy buyers seeking a base or an investment in a global, politically stable city.
But that has changed in 2015, in a shift that estate agents said was partly down to turmoil in emerging markets and partly to a change in stamp duty that means buyers of the priciest homes pay substantially more tax.
Asian homebuyers made up 26 per cent of those buying homes in areas such as Kensington, Chelsea and Belgravia in the first three-quarters of last year, but that number was down to 6 per cent in the same period of 2015, according to figures compiled exclusively for the Financial Times by Hamptons, a high-end estate agent.
Chinese buyers were down from 9 per cent of the total to 3 per cent.
Russians made up just 1 per cent of buyers in the prime London areas, which also include Knightsbridge and Mayfair, in the first three-quarters of 2015, down from 7 per cent a year earlier.
The fall has coincided with a period of turbulence in Chinese equity markets, which spread to other Asian emerging markets and prompted falls in the region's currencies against sterling. China's renminbi is down 6.6 per cent since April.
In Russia, the war in Ukraine and international sanctions, together with lower oil prices, have taken a big toll on the country's economy and currency. The rouble has shed 25 per cent against sterling since April and is down 53 per cent over the past two years.
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"These groups are not selling, but they are not buying either," said Charles McDowell, a Knightsbridge-based buying agent.
Fionnuala Earley, residential research director at Hamptons, said: "If you look at what's happening in the wider global economy, the trend makes sense — although it may be a blip and they may ultimately come back."
She said there were "tentative" signs that Asian owners were selling more prime London homes as a proportion of those on the market.
The market for expensive UK homes has been affected by sweeping changes to the stamp duty regime announced last December, which cut tax for most buyers but increased it for those buying homes worth more than £937,000.
This includes rates of 10 per cent on the portion of the sale price above £925,000 and 12 per cent on the part above £1.5m.
Total transactions in prime London boroughs were down 19 per cent in the first three-quarters of 2015 against a year earlier, according to figures from LonRes, with agents blaming the stamp duty rise.
UK nationals made up 42 per cent of buyers this year, against 36 per cent last year, Hamptons said, although relative demand from European Union countries remained strong.
Mr McDowell said uncertainty over the broader tax regime for overseas buyers was also playing a part.
"Foreign discretionary buyers are put off by stamp duty rates but also the complicated and high tax rates, with their advisers unable to advise, as a lot of the legislation is still being reviewed," he said.