London prices continue to grow at an incredible rate according to Knight Frank, which has recorded the highest monthly rate of growth in the capital ? 3.6% ? since its records began in 1976. It also says the annualised rate – 36.4% in the 12 months to July – is the highest rate since mid-1979.

One of the reasons for this huge leap in prices is the demand for top-level property in central London from foreign buyers, points out the agent. Over 61% of all property sales over £4m in this area go to buyers form overseas it says, who tend to hold onto their properties for a long time, and don?t release a property onto the market when they buy one.

?We have seen a phenomenal market in central London in recent years ? led by a strong City economy, very healthy bonus rounds and growing employment and population levels in London. But this is only one half of the story ? the demand side,? said Liam Bailey head of residential research at Knight Frank.

He pointed out that foreign buyers are keener to hang onto their property, even after their period in London ? be it for work or pleasure ? is over. Property in the capital is now seen as such a good investment that houses are not coming back onto the market in the way they used to. In 2004, according to this research an average foreign landlord letting a property after first having occupied it would only hold it for an average of nine months before sale. In 2007 the figure was 20 months, and is still rising, hence the idea that good London property is ?disappearing?.