A mother and her son were found dead at a house in Mirabazar area of Sylhet on Sunday noon.
The deceased were identified as Rokeya Begum, 40, and her son Rabiul Islam Rokon, 15, an SSC examinee.
Local ward councillor Dinar Khan Hashu said hearing the cry of the five-year-old daughter of Rokeya and smelling bad odour from the locked house neighbours opened the door by a duplicate key around 12:00pm and spotted the bodies.
On information, police recovered the bodies and rescued Rokeya's daughter Raisa from a room of the house, said Gausul Hossain, officer-in-charge of Kotwali Police Station.
Rokeya ran a beauty parlour in the city and her husband Helal Ahmed was paralysed for long and used to live in his brother's house.
Police said that they might have been murdered several days ago, reports UNB.
Poritosh Gosh, additional commissioner of Sylhet Metropolitan Police, said at a press briefing that the woman and his son were strangled and stabbed to death.