Homes in the capital averaged £501,056, increasing by 4.3% monthly and 26.1% yearly to command £103,671 more than April 2013..
Supply and demand accounts for the increase, as new buyer registrations increased by 11.7% annually while first-time buyer registrations rose by 16.7% in London.
Paul Smith, chief executive of haart, said: “The way to put the brakes on price growth is to increase supply but in London we have only seen new property instructions rise 0.2% annually and new properties for sale across the UK as a whole are down 1.7%.
“Homeowners can help break this cycle by putting their property for sale before finding somewhere themselves thus freeing up supply.”
Due to the rising prices in the South East many Londoners are being pushed into the 3% Stamp Duty tax band.
And Smith added: “The unfairness of this disproportionately South East-focused tax must be addressed before the next election.”
For the whole of the UK house prices increased by 9.4% annually and 2.1% monthly to £199,679.
First-time buyer registrations increased by 22.4% from last year, while new buyer registrations increased 10.8% annually despite an overall drop in supply of 1.7%.
There were 58,509 house sales in April 2014, an 18% annual increase.
Smith added: “Bubble talk needs to be burst – while UK house prices are rising they have not recovered to their 2007 levels.
“Although we are only a few weeks into MMR, growth in prices and interest in buying property have not been dampened.
“After all, stress tests are no bad thing and reassure both the lender and the buyer that the buyer’s income flow can support current and crucially future mortgage payments.”