Police recovered the throat-slit bodies of a couple and their son in Sonapahar area at Jorarganj union under Mirsarai upazila of Chattogram on Thursday morning.
The deceased were identified as Mostofa Mia, 70 his wife Josna Akter, 55 and their son Ahmmed Hossain.
Police detained Mostafa's elder son Sadek Hossain Saddam for interrogation.
The matter is being investigated. Details will be informed later.