Authorities are investigating the mysterious deaths of two illegal migrants, one Cambodian and one Vietnamese, while being detained at the Suan Phlu detention facility of the Immigration Bureau in Bangkok.

Pol Lt Kamonphop Ditsayabut, deputy chief investigator at Thung Maha Mek police station, said police were alerted to the two deaths at the detention centre at around 2.30am today (Oct 24).

The bodies of the two migrants were later sent to Chulalongkorn Hospital for an autopsy, he said.

One of them was a 55-year-old Cambodian man identified only as Sakhi and the other was a 72-year-old Vietnamese man known only as Robat, said Pol Lt Kamonphop.

They were detained for illegal entry in the southern province of Nakhon Si Thammarat before they were transferred to be detained at the Suan Phlu detention centre, he said.

Their bodies were found in a 6m x 4m detention room where a total of 15 people were detained together and no signs of physical injuries were found in a preliminary inspection, he said.

Some witnesses told police the two got up and went to the toilet before they returned to sleep before someone realised they weren’t breathing, he said.

Some detainees tried to wake them up but to no avail, he said.