The corpses of five women, one man and a young boy have been picked up since Thursday in the Srinakrin dam's reservoir, not far from the border with Burma, police said.

“I don't think that any more will be found,” provincial police commander Major General Rawat Klingaysorn said. “None of the bodies show signs of assault.”

He said they possibly died after their boat capsized. Police received a report of a boat accident on January 15 but never found the craft.

Humanitarian organisations estimate up to two million illegal Burmese migrants are working in Thailand, with many vulnerable to exploitation and denied basic rights such as medical care.

Maj-Gen Rawat said the number of people crossing the border had surged in recent weeks, as people from Burma head into Thailand to try to take advantage of an annual registration of migrant workers that begins on February 1.

Last month marine police in southwestern Thailand said 22 Burmese migrant workers died in a boat accident as they tried to enter Thailand illegally.

The two countries share a 2400km border, with the Burmese side largely controlled by rebel groups who have battled the ruling junta for decades.

News.com.au