Malaysia’s opposition and rights groups on Friday stepped up calls for the government to drop a plan to send home some of the Burmese citizens who have been detained for immigration offences.

Home Minister Hishammuddin Hussein this week announced a plan to send back an unspecified number of the roughly 1,000 people from Burma who are held in immigration detention centres in a bid to ease overcrowding.

Some Malaysians held in Burma would be sent home in return.

“We cannot proceed with such a swap as those who flee Myanmar [Burma] remain at risk of persecution from the military regime,” opposition lawmaker Lim Kit Siang told AFP.

The United Nations’ refugee agency also spoke out against the plan.

“Refugees and asylum-seekers… should not be deported to a country where their human rights might be at risk,” UNHCR Malaysia spokesperson Yante Ismail said.

Malaysia’s handling of refugees has come under scrutiny since a controversial swap deal earlier this year that would have seen Australia send 800 illegally arrived boatpeople to Malaysiain exchange for 4,000 registered refugees.

Rights groups had moved to block the swap out of concern for the fate of the boatpeople, and an Australian court eventually scuppered the deal.

Malaysia’s top rights group SUARAM earlier this week said those sent back to Burma would be in danger from its military regime and that the plan would legitimise a Southeast Asian nation known for its human rights abuses.

Malaysian officials have said poor standards and overcrowding in the country’s immigration detention centres had led to several breakouts in recent years.

Malaysia is not a signatory to the 1951 Convention on the Status of Refugees which governs the definition and rights of refugees and legal obligations of signatories.

Activists say Malaysia is used as a staging post for trafficking gangs engaged in moving people from Afghanistan and Burma to Australia.