The dead have been identified as Nur Alam, 59, and his son Anwar Mustafa, 12, residents of Kutupalong camp in Ukhiya.
They died at Chattogram Medical College Hospital on Tuesday, according to Superintendent of Police Naimul Haque, commander of the 14th Armed Police Battalion.
On May 12, Alam, his wife and two children were burnt when a fire broke out at his shanty when the gas stove pipe got disconnected during cooking. Two more neighbours were also injured while extinguishing the fire.
The locals took them to the nearby hospital and three of them were transferred to Chattogram Medical College Hospital in critical condition.
The bodies will be taken to the refugee camp after autopsy, the police officer said.