Highgate and Hampstead are home to two of the 10 most expensive streets to buy property in the country, with average house prices in the exclusive enclaves topping £10m.

Courtenay Avenue, N6, came fourth in Zoopla’s Property Rich List 2014 with an average property value of £16,877,746.

In sixth place was Frognal Way, NW3 where property is worth an average of £10,974,043.

Hampstead postcode NW3 is also the tenth most expensive area in the country, with property prices averaging just under £1.4m.

These prices represent relatively small change when compared with Britain’s most expensive street, Kensington Palace Gardens or ‘Billionaire’s Row’, which has an average property value of £42,730,706.

Lawrence Hall of Zoopla said: “London boasts all of Britain’s twenty priciest addresses. Prime properties in the capital have long been a magnet for the super-wealthy looking for a safe investment asset.

“For the lucky few who can afford these stratospheric pricetags, the fabulous mansions on streets like Kensington Palace Gardens and the Boltons are offering very strong returns.

All of the top ten most expensive streets were in London but the number of property millionaires across Britain has almost doubled since last year and now stands at nearly half a million.

There are also 10,613 streets – up a third from last year – with an average property value of more than £1m.