Their deaths are the latest in a tumult of violence and intrigue to shake tourism in postcard-perfect Thailand, raising questions over whether it is squandering a prized asset by failing to protect travellers arriving in record numbers.

Other headlines are less dramatic but equally troubling: taxi driver mafias, transvestite thieves, pollution, tourist brawls, traffic accidents, and at airports, radar glitches, flight delays and long immigration queues.

"The Tourism Authority of Thailand TAT.L think numbers are going up so people must like it here, but the problem is the quality of their visit has gone down," said Larry Cunningham, Australia's Honorary Consul to Phuket, an island described by travel guide Lonely Planet as "one of the world's most famous dream destinations".

The government has vowed to tackle "mafias" in tourist areas, while in February, Cunningham appealed to Phuket's government to stop jet-ski operators who hire thugs and demand compensation for equipment damage renters did not cause.

Last year, a German television show broadcast footage of sewage pumped into the sea at popular Kata and Karon beaches.

The problems have so far failed to dull Thailand's centuries-old exotic allure. Its palm-fringed islands, gilded temples, spicy cuisine and racy nightlife helped draw 19 million visitors in 2011, generating 776 billion baht in revenue, up 31 percent from 2010, ministry data shows.

Even so, tourism's contribution to GDP has barely increased since 2003 and now hovers at 6 percent. And with unspoiled destinations in neighbouring Myanmar opening up, Thailand is under pressure to decide what type of tourism it wants.

Phuket, for example, is at risk of sharing the same fate as another beach destination: Pattaya.

"SIN CITY"

A two-hour drive from Bangkok, Pattaya struggles to shake off a seedy reputation as Thailand's "Sin City" and with red-light entertainment, crime and unchecked development, it is synonymous with sleaze and spoiled beaches.

"We still think of tourism too much in a opportunistic, money-making way," said opposition lawmaker and former finance minister Korn Chatikavanij. "We are putting the future of the industry at risk."

Tourist safety is another pressing issue.

The Fédération Internationale de l'Automobile FIA.L- a motor sport governing body - shows Thailand has the highest U.S. tourist road fatality rate in the developing world, after Honduras. Britain's foreign office warns of robberies and "vicious unprovoked attacks by gangs" on the party island, Koh Phangan.

Some tourists say standards fell short of expectations.

"In general Thailand feels safe but tour guides and drivers are more aggressive," says Mattias Ljungqvist, 31, a Swede who first visited the country a decade ago.

The TAT says it does not have regulations to tackle crime head on and safety and environmental preservation issues are encumbered by local bureaucracy.

But with plans to promote Thailand to new markets in South America and Central Asia, there is little evidence of its tourism ambitions slowing down.

Thai Prime Minister Yingluck Shinawatra last month said the government's tourism policy would focus on generating 2 trillion baht in revenue within five years. The Ministry of Tourism and Sports plans to spend 2.6 billion baht on developing and promoting tourist attractions in 2013.

It hopes to attract 21 million visitors this year, among them big spenders.

"People who enjoy eco-tourism tend to spend a lot of money and we are definitely targeting that type of tourist," said Chattan Khunjara Na Ayudhya, a public relations director at TAT. (Editing by Jason Szep, Andrew R.C. Marshall and Ed Lane)

• A Permanent Economic Emergency