Firefighters recovered the body of Sajidul, 7, on Wednesday morning, Navy Commander Rayhan told the Dhaka Tribune.
The rescue operation has been called off, he added.
Sajidul went missing after the two-storey building collapsed on the Kaptai Lake on Tuesday evening. Bodies of four people were recovered till the night.
Five people were rescued in the rescue mission jointly conducted by firefighters, army, navy and police.
The building collapsed around 5:30pm near at Mohila College Gate area of the town. The causes behind the collapse are yet to known.