The migrants tell of secretive, brutal treatment by Thai security services
A shocking story is unfolding in Thailand. Migrants and refugees who turn up on its shores have testified that they are being sent back to sea in boats without engines, their hands tied, left to their fate.
Hundreds are thought to have suffered this treatment - among them many Rohingya people of western Burma - and many have died. The BBC's Jonathan Head in Bangkok has been investigating what has been happening.
The 46 Rohingyas who arrived by boat at Phrathong Island on Friday morning may be lucky.
Like the hundreds of other asylum-seekers from this Burmese Muslim minority who have arrived on Thailand's Andaman Sea coast, they have been handed over to the Internal Security Operations Command (ISOC), a military authority set up under the Cold War and still given sweeping powers to protect national security.
That means they disappear into a black hole. No visits from lawyers or refugee advocates. The military can do what it likes with them.
But after the spotlight now being shone onto the treatment of previous Rohingya groups, this one may be handled more leniently.
Harsh treatment of asylum-seekers is nothing new in Thailand. But the allegations made by Rohingyas who have drifted hundreds of kilometres to the Andaman Islands and Indonesia's Aceh province are shocking.
According to a local civic group, the Arakan Project, whose staff have done extensive interviews with some of the survivors, they were detained by the Thai security forces in late November and December last year as they arrived by boat.
Instead of being handed over to the police or immigration for processing as illegal immigrants, they were instead taken by military units to an island called Koh Sai Daeng. They were detained there for several days, sleeping out in the open, their hands tied at night.
On 18 December one group of just over 400 was put on a navy boat, which was towing a barge behind it, says Chris Lewa from the Arakan Project.
Their hands were tied. Once out at sea they were ordered to move onto the barge at gunpoint. They refused. The Thai troops then tied the feet of four of them and threw them overboard.
The group then moved onto the barge, and the rope was cut, leaving them with food and water for two days.
They drifted for more than 10. According to the testimony she has obtained, Ms Lewa says they sighted land - the Andaman Islands - on around the 12th day.
Fearful that the current would sweep their barge away, many of the exhausted and dehydrated Rohingyas leapt into the sea to try to make it to land.
Fewer than 100 were found on board by the Indian coastguard, although an unknown number was also picked up from the sea or on beaches.
Briefer telephone interviews with survivors by the BBC have confirmed this account. Survivors who reached Aceh have told the local media the same thing.
In all, more than 800 Rohingyas were expelled in this way in December. Hundreds may have died.
The local commander of ISOC in Ranong, Col Manas Khongpan, has denied these allegations. He told the BBC that illegal immigrants are never held by his troops.
But that contradicts comments the BBC has been given by other military and police officials, who say all Rohingya boat-people are now being handled by ISOC.
Some of the lucky survivors were picked up by the Indian coastguard
Some of those officials, who did not want to be named, confirmed that Rohingyas had indeed been set adrift at sea, with little food and water.
They explained that Rohingyas are seen as a greater security threat than the tens of thousands of other illegal migrants, because they are Muslim, because they tend to arrive in large numbers at one time, and because they are almost exclusively men.
Immigration officials told us there is no evidence to support the allegation made by some in the military that Rohingyas have gone to Thailand's deep south to join the Islamic insurgency there.
The officials have told us that while most of the Rohingya want to go to Malaysia - where there is already a community 20,000 strong and the prospect of well-paid jobs - increasing numbers are staying in Thailand. The official figure last year was 4,886, and the unofficial figure may be much higher.
The Thai government has now issued a statement saying it is investigating all the facts surrounding these allegations.
It has promised to re-assess the situation of all illegal immigrants in Thailand, numbering perhaps three or four million, most of them from Burma, and to treat them in accordance with humanitarian principles.
Whether it can truly hold the military to account though is open to doubt. In many areas of Thailand the army operates with little civilian oversight. It has huge secret budgets, and extensive business interests.
The current Democrat-led coalition was stitched together last month thanks to the intervention of the powerful army commander General Anupong Paochinda - he may well resist any calls for his men to be brought to justice over these allegations, as his predecessors have.
But it is also worth remembering that under the most recent constitution the most senior commander of ISOC is, in fact, the Prime Minister Abhisit Vejjajiva.
He has made the rule of law one of the core principles of his administration. Any crimes committed by ISOC personnel, whether against Thais or illegal migrants, will ultimately lie at his door.