Little evidence remains of the December 2004 tsunami on the palm-fringed white sand beaches that stretch for 200 kms north from the Thai resort island of Phuket to the Myanmar border.

International holiday makers have flocked back to one of the world's top tourist playgrounds rebuilt mainly by migrant labour from Myanmar less than three years after the disaster levelled hotels and fishing villages alike, leaving over 8,000 dead and tens of thousands displaced.

For Aye, a 28-year old Burmese migrant who earns THB 100 (USD 3) a day as a bricklayer in the resort of Khao Lak, the tsunami brought tragedy when her younger brother, who worked on the same building site, died.

"Our boss recognized the tsunami and drove us from the site to high ground in time. But my brother was collecting building materials in a pickup with another man and they both drowned," she says.

"When we came back to the site we saw their bodies laid out on the beach, but the police told us that we couldn't take them as they had to be formally identified at the police station. But we were afraid that they would arrest us if we came back," she explains.

A year later, encouraged by an older brother from Myanmar and with help from IOM/Ministry of Public Health community health workers, Aye went to the Phang Nga Thai Tsunami Victim Identification (TTVI) morgue to provide a DNA sample and formally claim her brother's body from hundreds stored in refrigerated containers – many of them other Burmese migrants whose families were also too afraid to claim them.

For the estimated 2 million Burmese migrants working both legally and illegally in Thailand, fear of arrest and deportation to Myanmar – a country in economic and political turmoil – is a daily reality. The lack of economic opportunities back home means that even the worst jobs in Thailand's flourishing economy are an opportunity that few will pass up.

"If they are deported from (the southern city of) Ranong, they can usually find a way to come back. But if they are deported from Mae Sot (further north), there is a much higher risk of being robbed or ending up as forced labour for the Burmese military," says Aye's sympathetic Thai employer in Khao Lak.

Like many Thai employers, he values the Burmese as good workers whom, he says, work harder and for less money than their Thai counterparts.

But a complicated and relatively expensive registration process for migrant workers in Thailand means that many Burmese and their Thai employers still avoid legal registration – leaving employers liable to prosecution and workers uninsured and exposed to potential abuse.

IOM Thailand's labour migration programme manager, Vipunjit Ketunuti, who manages a USAID-funded IOM project that informs migrant workers, employers and local government officials about labour migration law, rights and obligations, says that confusion and lack of information has led some provincial Thai governments to introduce new legislation that is actually exacerbating the problem.

"Employers and migrants who respect Thai law and register with the authorities should be encouraged and protected. But new legislation introduced in four border provinces this year to improve the regulation of migrant workers will likely be counter-productive," she says.

In Phang Nga, where Aye works, and on the holiday island of Phuket for example, registered migrants are now subject to an 8:00 pm to 6:00 am curfew. If they are picked up by the police at any time without their identity papers, they risk immediate deportation.

They are forbidden to travel outside the province in which they work without special permission and are not allowed to drive cars or motorcycles. They are also banned from gathering in groups of more than five people and not allowed to own mobile phones without the prior approval of their employer.

"The legislation requires employers to only hire registered workers and to provide them with decent accommodation. But while employers may face small fines for non-compliance, legally registered migrants are now theoretically at greater risk of deportation than before," says Ketunuti.

For many low-paid Burmese migrant workers already reluctant to pay an annual registration fee that represents over a month's wages and wary of using the Thai public health services to which it entitles them, that may tip the balance between working legally or illegally in Thailand.

In addition, few legal channels exist for Burmese workers wanting to work in Thailand, so most enter the country illegally. Thailand has not offered irregular migrants the opportunity to register and regularize their status since 2004.

Migrants who are already registered and have work permits are allowed to renew them annually for THB 3,800 (USD 112), of which THB 600 is for a medical check up and THB 1,300 for health insurance.

But many Burmese migrants rely on middlemen to process their applications, increasing the cost by as much as 50 per cent – representing another disincentive to renew their work permits each year. "Some unscrupulous employers also see an upside in hiring irregular migrants who exist on the margins of Thai society, living with the risk of summary deportation and powerless to negotiate their terms and conditions of employment," says IOM regional labour migration specialist, Federico Soda.

But the Thai authorities are acutely aware of the social, public health and other risks associated with marginalizing some 1.5 million irregular migrants and their families living in Thailand and driving them underground, according to Ketunuti.

"Marginalizing a generation of migrant kids by excluding them from education or excluding migrant communities from national preparedness plans to combat a bird flu pandemic or a second tsunami are now widely recognized as issues that have to be addressed by government," she notes. "IOM's migrant rights project in Thailand is designed to support government efforts to cope with these challenges. By bringing together government officials, employers and migrant workers through sharing information and building trust, we believe that we are contributing to a more transparent system that will eventually optimize the obvious economic benefits of labour migration, while protecting the human rights of migrants and their families to an acceptable international standard," she adds.