Estate agents like to brag about setting new records for prices, but when the seller is Sheikh Hamad bin Khalifa al-Thani, the Emir of Qatar, a little more discretion is called for. So even though his north London home — at £65m — is the most expensive private house on the market in the city, don’t expect to read its details on a card in an agent’s window.

That is if Beechwood, which lies behind elaborate wrought-iron gates in 11 acres of manicured lawns and woodlands off Hampstead Heath, can really be said to be “on the market”. No brochures have been produced, and only a few hand-picked individuals have been invited to view. The stucco-fronted house, dating from 1840, apparently has at least six bedroom suites, bags of reception space and a state-of-the-art security system, but ask usually loquacious agents for more details and they become tight-lipped and nervy.

“It is luxurious but dated,” says one property expert who has visited the house. “It obviously had a lot of money spent on it in the 1980s, but anyone buying it now would want to start again. It is very special, though. The site is fantastic.” Another says, somewhat less enthusiastically: “It is very Middle Eastern. I can see the site appealing to a developer.”

The emir, 56, who graduated from Sandhurst before overthrowing his father in a bloodless coup in 1995, bought Beechwood in the late 1970s. He has made his mark, building an indoor swimming pool and converting the squash court into extra staff accommodation.

Like many of the super-rich who bought in Hampstead and on swanky Bishops Avenue, the emir is moving to central London. He is thought to have paid £37.5m for 100 Park Lane, currently an office building that, for a further £10m or so, he intends to turn into a grand family home with 17 bedrooms, 14 reception rooms, a double-height ballroom, an 81ft picture gallery and swimming pool. It also has four staff flats and 26 parking spaces — ideal for his extensive car collection, described by one visitor as “Mercedes after Mercedes after Mercedes”.

So who will buy Beechwood? Rich Russians are the most obvious target group: Michael Cherney, 54, a leading Russian-Israeli oligarch, is thought to have expressed interest. It would also appeal to a developer who could pull down the house and replace it with something larger.

Such properties do not shift overnight, of course. Old Swan House, on Chelsea Embankment, has been on the market for £32m for several months, while Updown Court, a vast marbled mansion in Windlesham, Surrey, priced at £70m, has been awaiting a buyer since 2005.

Not that this will persuade the emir’s agents to adopt more aggressive sales tactics. “Buyers at this level don’t want to be seen to be so wantonly extravagant,” says Robert Bailey, whose eponymous agency specialises in finding sumptuous homes for the super-rich. “Both sellers and buyers prefer to make it known discreetly to a select group of interested parties that it is available.”

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