The claim, if verified, adds a deeply troubling new dimension to the alleged mistreatment of Rohingya by Thai authorities - that they not only turned back to sea recently arrived boat people but also loaded some of the 20,000 Rohingya living in the country into boats and set them adrift.

In an interview with Aceh's leading newspaper, Serambi News , one of the 198 Rohingya rescued by the Indonesian Navy, a Malay speaker called Rahmat, said among those in the crammed 12-metre wooden boat were people who had been bakers, fishermen and timber workers in Thailand, including himself.

"I have been working for one year in Thailand. My wife and child still in Burma," the newspaper quoted Rahmat as saying. As with most Rohingya, he was living in Thailand illegally.

Rohingyas are a Muslim minority from Burma who claim persecution at the hands of its military junta.

Speaking from his hospital bed, he said 1000 Rohingyas had been rounded up by Thai military officers, taken to an island for two months, then set adrift in boats in mid-January.

Quarantined on the island, the Rohingya say, they were whipped and beaten. They showed scars they claim were caused by the mistreatment.

Rahmat said his boat was at sea for almost three weeks with no engine and little food and water, before Indonesian fisherman saw it in the Strait of Malacca and alerted authorities.

"During the journey about 20 people among us died because there was no food and water. We performed prayers in the boat for them before we threw the bodies into the sea," he said. "Almost every day someone would die."

Chris Lewa, co-ordinator of Bangkok's Arakan Project, which has long been a Rohingya advocate, said reports of a round-up in Thailand had been reaching her for days but remained unconfirmed.

Ms Lewa said there had been three separate incidents where Thai security forces towed wooden boats without engines to sea laden with Rohingyas in the past six weeks. The first occurred on December 18 involving 412 people, the second on December 28 or 30 involving 580 people and, as revealed this week, a third flotilla was set adrift in mid-January with up to 1000 Rohingya aboard. No other boats have been found from the last flotilla.

Refugee groups are urging Indonesia to launch a sea and air rescue, so far in vain.

Thailand's foreign ministry did not return the Herald's calls yesterday but the Foreign Minister, Kasit Piromya, dismissed the latest allegations of mistreatment as unverified.

Indonesian foreign affairs officials, members of the International Organisation for Migration and translators are due in East Aceh tomorrow.

Nasrudin Abubakar, East Aceh's deputy regent, said the local community was willing to take in the Rohingya, "especially because they are Muslims. We have to help." Islamic boarding schools would take 20 people each."