Two men, an elderly Vietnamese amputee and a Cambodian, were found dead without any obvious wounds in a cell at the Immigration Bureau headquarters in Sathon district of Bangkok early on Wednesday morning.

Police at Thung Mahamek station, situated beside the bureau, were informed of the death of the two illegal migrants about 2.30am.

The Cambodian man was identified only as Saki, 55. He was wearing a green shirt, brown jacket and green shorts. He had been caught in Nakhon Pathom province and transferred to the Immigration Bureau prison in Bangkok.

The Vietnamese man was identified only as Robert, 72. He was an amputee, missing his right leg, and was wearing a blue shirt with white stripes and an adult diaper. The man had been caught in Nakhon Si Thammarat province.

They were in Cell 14B on the first floor. It is four metres wide and six metres long and 15 people were being detained in there.

The two bodies were taken to Chulalongkorn Memorial Hospital, police said.

Pol Maj Gen Surachate Hakparn, acting immigration chief, later quoted doctors as saying that both migrants suffered from pneumonia. The Vietnamese man also had a heart disease and tuberculosis.