£7m for home in London's most expensive street (apparently)

Properties in Courtenay Avenue, Hampstead, sell for an average of £6,803,900, the highest level for any street in the capital.

The cul-de-sac, near Hampstead Heath and Kenwood House, boasts large detached properties, many with swimming pools and expansive gardens.

The boom in property sales at the top end of the London market is being driven by foreign buyers such as Russian-Israeli diamond billionaire Lev Leviev, who paid a reported £35 million for a property in Courtenay Avenue known as Palladio.

The capital's second most expensive address is Chelsea Square, SW3, where houses are typically worth £6,440,600. Average prices for the mainly three-storey Thirties terraces, which are home to famous names including Jemima Khan, rose more than £1 million from £5,098,047 last year. Manresa Road, which runs into Chelsea Square, emerged as the third most expensive street, with a number of terraced Fifties houses as well as very expensive apartments, some of which have been converted from the old Chelsea College of Art. Surprisingly, so-called "Billionaire's Row" - Bishops Avenue in Barnet - is not in the top 20 streets, despite having properties worth £41 million, as it also contains a number of lower priced homes, reducing the average. The figures, from house price website Mouseprice, show that prices in London's 20 most expensive streets continue to soar. Last year's top street was Kensington Square in W8, in which the average price was £5.5 million.

Of the current top 20 streets, 15 are in Kensington and Chelsea, while areas near Highgate and Hampstead golf courses command the next highest prices. Average prices in the top 13 addresses are all above £5 million for the first time.

The figures show how the gap between London's top prices and those elsewhere in the country is getting wider. The 10 most expensive London streets have average prices about 60 per cent higher than those in the South-East, but they are three to seven times higher than top prices in other regions.

The list of of the most expensive streets comes after the Standard revealed computer images of the interior of the world's most expensive flat - the Candy brothers' £100 million One Hyde Park penthouse. Due to be completed in 2010, the flat will be the centrepiece of an 80-flat development managed by brothers Christian and Nick Candy.

Half the units have been sold at an average of more than £20 million each, with average per square foot prices of £6,000 - around double that of anywhere else in the world.