"There are many individual tragedies among the Chinese community and tourists are being driven away."

The alarm was raised after an application for a tenth betting shop was lodged last month for 47 Gerrard Street in the heart of one of the oldest and largest Chinatowns in the world.

Betting outlet Hoolabet have applied for a gambling licence for a two-storey building which until recently was occupied by one of the area's longest established restaurants, The Friendly Inn.

If, as seems likely, the latest licence is granted by Westminster Council, Hoolabet will be operating next door to a branch of Ladbrokes - the UK's largest betting group.

Other bookies nearby include Paddy Power and Betfred, which runs a shop at the other end of Gerrard Street. The betting shops have Chinese characters on their signs to attract Chinese customers.

But Yau said: "People come to Chinatown to eat Chinese food and buy Chinese goods and soak up our culture. What do they see now? Nothing but betting shops.

"It is bad for Chinatown, bad for London and really bad for the image of Chinese people."

Though betting on horse races is offered, most punters play the highly profitable online slot machines which demand £100 (HK$1,210) per play.

Revenue from the machines - which are limited to four per outlet - typically account for about half the annual turnover of each betting shop. Last year, the slot machines made £1.5 billion for UK betting firms.

Local councils have only limited powers to reject applications for betting shops, though Westminster officials said they were trying to persuade the government to grant town halls more control. "It is these slot machines which are causing addiction and destruction," Yau said.

She has written to London Mayor Boris Johnson and the British government's Secretary of State for Communities and Local Government, Eric Pickles, demanding action.

Simon Thomas, a spokesman for the gambling addiction charity GamCare and owner of the Hippodrome casino in London's Leicester Square, said one third of all the calls to the help centre are directly related to gambling machines.

He added: "No other country in the world would allow £100-a- go gambling machines on their high streets. Chinatown is being turned into a betting shop strip."

But with the government enjoying strong tax returns from the machines and the betting industry spending millions on lobbying for less regulation, many fear little will be done.

"Many in the Chinese community are conscious of the problems, pain and harm inflicted on their families by their gambling, but they simply cannot help it," Yau said.

"They can walk by one betting shop, but not the second or the third. The temptation is much stronger than their will."

Peter Chan, of the Christian Centre for Gambling Rehabilitation, said language and cultural barriers plus anti-social working hours meant many of members of the Chinese community were drawn to gambling.

"When they are off work there is nowhere for them to go - only the casinos or the betting shops," he said. One man gambled away about £2,000 a day and lost his business, Chan said.

But the Association of British Bookmakers said betting shops would open "where there is customer demand".

Spokesman Peter Craske said: "In Westminster you've got 240,000 residents and a million people visit a day. It's one of the busiest, most densely populated areas in the country.

"So of course there will be more betting shops - the same as there are more restaurants."