Britain's rich are selling up and moving out of the smartest neighbourhoods of their own capital city, replaced by a wave of super-rich migrants who have more money to spend on high end property, new research found.

Upmarket property consultant Savills said increasing numbers of British homeowners were relocating from London's best districts where British sellers of homes have outnumbered buyers by 30 percent this year, compared with 7 percent in 2008.

Foreign buyers outnumber sellers by 58 percent in 2011, up from 23 percent in 2008, the research found.

Foreign buyers inject more than 3 billion pounds ($4.9 billion) into London property each year, Savills said, the bulk of which -- 2.7 billion -- wais used to snap up homes in billionaire enclaves like Chelsea and Mayfair.

"London property is one of the country's biggest exports," said Yolande Barnes, head of Savills Research.

Foreign buyers were being drawn to London's cultural attractions as well as political and financial stability, particularly in the context of revolutions across the Arab world and southern Europe's debt crisis, she said.

The biggest spenders on high-end London property come from eastern Europe and the former Soviet Union, with an average spend of 6.2 million pounds, Savills said, followed by Middle Eastern buyers who put down 4 million on average.

Indians spend 3.4 million pounds while Chinese, widely tipped as the next group to arrive in force and join more established communities of wealthy Russians, Indians and Arabs in London, have been spending 2.2 million pounds on average.

The British spend, on average, 1.5 million pounds on prime London property.