Thai immigration authorities, fearing human smuggling gangs were preparing to traffic Sri Lankan Tamils to Canada and Australia, arrested 130 Tamils in a sweep of residences in Bangkok, South Asia diplomatic sources said.
The raids took place earlier this week and followed joint intelligence operations with Australian and Canadian authorities, sources said.
Media reports said the raids followed pressure by Canadian authorities amid fears the refugees were readying to travel to Canada aboard a smuggling ship.
In August, a ship identified as the MV Sun Sea had brought 492 Tamil asylum seekers to Canada after another vessel, the Ocean Lady, transported 76 Tamils to the British Columbia coast.
The Canadian Government has adopted a harder line towards asylum seekers after the MV Sun Sea arrived in Canada.
Australian Prime Minister, Julia Gillard, during the recent election campaign, said her government would adopt a tougher policy to deter boat people coming to Australia.
But diplomatic sources say those arrested had been living in Thailand up to four years after overstaying tourist visas.
The refugees are due to appear before a Thai court Wednesday to face fines of 500 baht ($A18) a day for each day they had overstayed their tourist visas or a jail term until the fines are met. In both cases the Tamils are expected to be deported back to Sri Lanka.
The senior diplomat said the refugees, whom he met at the immigration detention centre, denied being linked to any plans to be smuggled to Canada or Australia as boat people.
They are all people who have applied to the UNHCR (United Nations High Commission for Refugees) for refugee (asylum) status and they have been waiting (in Thailand) until their applications have been determined, the senior diplomat said. So most of them have overstayed their visas and that is why they have been arrested, the diplomat told AAP, requesting anonymity.
There was enough intelligence to suggest there were large groups of Sri Lankan Tamils hanging around (Bangkok). What the police did was they raided the places they were staying and arrested the whole lot, he said.
But only to find they have been staying here for a long time and not actually waiting to board a ship, he said.
The asylum seekers told the diplomat they had taken the legitimate route and had not been looking to jeopardise efforts at being granted asylum.
They also told him they could not afford the smugglers fees that for Australia amounted to around $US20, 000 ($A20, 381) and for Canada as much as $US40, 000 ($A40, 762). He said such people make their journey to Thailand intending to stay a short while before being smuggled out their final destination.
AAP attempted to contact the UNHCR, but a spokesman was not available for comment.
But Human Rights Watch (HRW) criticised the Thai authorities. HRW representative in Thailand, Sunai Pasuk, said the rights group was concerned that Thai authorities were readying to send the Tamils back to Sri Lanka without proper screening.
Western governments were critical of the Sri Lankan Army’s tough measures to end decades long fighting with claims of thousands of Tamils killed in the final push in May last year to end the conflict.
Pasuk said the people remained at risk upon their return to Sri Lanka. Sadly, the record of the Thai government on (screening asylum seekers) on that front is very poor, he told AAP.
The Thai government shows no respect in their international commitment to protest asylum seekers, he said. So this may end up being another sad case of people who deserve to be put under international protection but end up being deported by the Thai state to the place where they will be in danger, he said.