Sales of “super-prime” properties in central London – those worth more than £10m – have increased significantly over the past few months, as demand for trophy homes from both overseas buyers and domestic purchasers has grown.

Transaction volumes for these luxury homes in the capital rose by 63 per cent in the three months to the end of May compared to the same period last year, according to figures from Knight Frank, the upmarket property agent.

The number of sales in the £3m-£5m and £5m-£10m price bands also increased, up by 14 per cent and 27 per cent respectively. In comparison, the number of transactions in the £1m-£3m London price band rose by 10 per cent, while sub-£1m property sales fell by 10 per cent.

Figures from Savills, the estate agent, show a similar picture. It recorded a 4 per cent fall in transactions involving sub-£1m London properties, but a rise in all higher price brackets.

Agents say that a significant driver of the increase in £1m+ property sales was the introduction in April of a new 5 per cent stamp duty rate for properties bought for more than £1m. They report a surge in activity all over London, as buyers rushed to exchange on deals ahead of the tax change.

“The stamp duty increase definitely skewed the market in March and brought forward a good number of sales,” says Noel de Keyzer of Savills’ Sloane Street office. “April was very slow by comparison, not least because of the unusual number of holidays.”

However, agents say the boost in transaction volumes is also down to an increased confidence in the prime London property market in recent months.

In the last week alone, Savills’ Sloane Street office has agreed four house sales at the £5m+ end of the market. Similarly, Charles McDowell, a property consultant, says he has recently arranged sales of two properties worth more than £20m.

Andrew Giller, head of London at The Buying Solution (TBS), a buying agent, says it is seeing demand from UK-based international families who have generated a lot of wealth in the last two years and now want to upgrade to larger family houses for £10m+ in Chelsea, Notting Hill, Holland Park and Kensington.

Giller believes that, in turn, more property is being released onto the private market because sellers realise that they can achieve premium prices, whereas last year buyers were more cautious and vendors – who were in no rush to sell – held back.

Statistics from LonRes, a service for estate agents that records transactions in London, shows that around 150 new properties in the £3m-£5m band were suddenly listed in a single week after the Bank Holidays. James Bailey of Henry James, an estate agent specialising in properties in Belgravia and Chelsea, believes this is about a 60 per cent increase on listings at the beginning of the year.

“The market has certainly changed and we have seen a steady stream of new instructions since April,” says Bailey.

There are also signs that domestic buyers are returning to the prime London market. Simon Hedley of Druce, an Marylebone-based estate agency, says that approximately 60 to 70 per cent of all its buyers in Marylebone are British, up from only 40 per cent before. He says the majority of the more expensive properties – between £2,000 and £2,500 per square foot – are going to UK buyers.

Giller of TBS believes the rise in sales volumes in the £5m-£10m price bracket is down to City money, with many buyers who sat tight in 2009 and 2010 now looking for property. Savills has also seen evidence of bonus cash in the market, with buyers looking to upsize their homes.

Savills’ figures show that the number of buyers from the financial services sector was up by 18 per cent in the three months to May, compared with the same period last year, while in prime south-west London they were up by 69 per cent.

“More of our sellers than in previous years, currently some 65 per cent to 70 per cent, are trading up in London,” says Robin Chatwin of Savills Wandsworth.

However, the big increase in transactions in prime London has not yet filtered through to the prime country locations in the south-east and south-west of England. Figures from Knight Frank show that sales in prime country were down in all of the price brackets between £1m and £10m, compared to last year.