Many wealthy homebuyers are drawn to the political stability of London and the buoyancy of its property market. But concerns about the kind of lawlessness typical of their home countries or fears of reprisal from business or political opponents mean they demand the most hi-tech security systems around.

"I recently showed a property to a billionaire eastern European and when he walked outside I presumed he had gone to look at the wonderful garden," said Andrew Langton, managing director of high-end estate agent Aylesford. "He was actually inspecting the buildings that overlooked it."

Overseas investment in top London homes used to be dominated by Middle Eastern oil money and U.S. bankers, but the current financial crisis and political tensions in areas like North Africa and Russia mean over 100 nationalities now park money in top London property, said property agent Savills (SVS.L).

The capital does not have the same reputation for danger as cities like Cape Town or Rio de Janeiro, but incidents in recent years demonstrate overseas residents are not necessarily safe from their foes in London.

In 2009, former Russian spy Alexander Litvinenko was killed with radioactive polonium in London. In March this year, a Russian banker was shot five times and badly injured, later claiming his former business partners were behind the attack.

NO GUARANTEE

Russian tycoon Boris Berezovsky, a Kremlin insider-turned-critic now based in London, told Reuters: "There is no place safer than London from Kremlin bandits or from Russian or international criminals. But that of course is no guarantee they won't get you."

Not every buyer faces such dramatic personal threats, but many fear crime because it is prevalent in their native country. "If you are a rich Eastern European you have been brought up in fear of others 'borrowing' your possessions," Langton said.

One Hyde Park, a development in which the most expensive flat sold for 136 million pounds, has panic rooms and bullet-proof windows.

A 16 million-pound house on sale in the district of Kensington includes two panic rooms, two separate CCTV systems, safes for 24 guns and ammunition, bullet-proof windows and machinegun-proof doors.

Measures previously used by museums to protect artwork such as "security fog" are also now more common in homes, said Edo Mapelli Mozzi, managing director at consultancy Banda Property. Rooms fill with a thick fog in seconds to disorient intruders.

International security company Westminster Group (WSG.L), which provides services ranging from military training to fire safety, increased turnover to 10.1 million pounds from 3.8 million in 2011. It cited contracts won for "several high-net-worth properties in the UK including a stately home".

"We are seeing more out-of-the-ordinary security with the huge influx of foreign investment in London," said Westminster sales director Shires Crichton, referring to measures including armoured cars and 24-hour surveillance.

The company also carries out pre-sale threat assessments. "An alleyway down the side of a house can make it easier to snatch someone," said Crichton. "We also ensure there is nobody living nearby they don't get on with."

The risks aren't necessarily greater now in London but the insecurities people bring with them are, said Stephan Miles-Brown, head of residential development at property consultant Knight Frank.

He said there was more state-of-the art security in London homes because it was more readily available. "A few years ago, everyone was demanding air conditioning as a 'must-have'. Now their attention has turned to 24-hour concierge teams and state-of-the-art security systems."

Despite the gadgetry, traditional methods such as bodyguards are still widely used, said Langton. "The main form of security used still seems to be someone hanging around who's not a member of the family." (Editing by Andrew Roche)

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