Prime Minister Abhisit Vejjajiva told CNN that while he was unsure who in his government approved the practice of sending Muslim Rohingya refugees back to sea, he was rectifying the situation.
"It's not exactly clear whose work it is," Vejjajiva was quoted as saying. "All the authorities say it's not their policy, but I have reason to believe some instances of this happened, but if I can have the evidence as to who exactly did this I will certainly bring them to account."
Thousands of Rohingya refugees have tried to flee Myanmar, where they are persecuted, CNN reported.
Vejjajiva said "at times" there has been "a lot of pressure in terms of the numbers of these people coming in" from Myanmar.
"There are attempts, I think, to let these people drift to other shores," he said. "I have asked whether people are aware of such practices. The one thing that is clear is that when these practices do occur, it is done on the understanding that there is enough food and water supplied."