The victims were identified as Rais Uddin, 52, his wife Salma Begum, 46, their son Rajib and daughters Yuona, 28, Swarna, 18 and niece Urmi, 8, who was also adopted as a daughter.

Police recovered the bodies in the afternoon breaking open the doors locked from inside and sent those to Narsingdi Sadar Hospital morgue for autopsy. The brutal murders might have taken place some six days back, the police believe. The murderers entered the house cutting open the grills of a window, it was found.

Two of the victims were slaughtered while the rest were strangulated to death and bore deep wounds in the foreheads. The bodies of two females were undressed. Quoting hospital officials, police said that one of them might have been raped before killing.

"It is a case of cold-blooded and well-planned murders," Mohammad Shahabuddin, superintendent of police (SP) of Narsingdi, told The Daily Star. Dispute with someone might be the cause behind the murders, he suspects.

Police picked up Abul Kalam, a nephew of Rais, for interrogation.

The district administration formed a three-member committee with Additional District Magistrate Kazi Nazir Hossain as its chief to probe the murders.

The gruesome incident came to notice when Abul Kalam came to the house yesterday noon and smelt stench coming out of the house. Police rushed to the spot after he informed them.

Several hundred people of the locality thronged the spot hearing the news.

Officials of Criminal Investigation Department (CID) and Detective Branch (DB) of Police visited the house and collected evidence.

According to the victims' relatives, they had moved to the town some three months back from Chinishpur village selling out their ancestral lands and since had been living in the one-storey rented house surrounded by concrete walls. An expatriate Bangladeshi Maznu Mian owns the house.

Rais Uddin, who had an electric appliance shop, sold his land at around Tk 5 lakh to send his son Rajib abroad, but Abul Kalam took a major portion of the money as loan from him, they added.