TV cable service operator Dipak Bhattacharya, his 84-year-old mother Gouri Bhattacharya and two women domestic helps were found dead with their throats slit, at a house on Biren Roy Road West on Thursday.
"All the four culprits were arrested from their residence at Haridevpur and Bishnupur in South 24 Parganas district. They have admitted their involvement in the crime," city Police Commissioner R K Pachananda told reporters here.
The four men were interrogated by detective department officials and produced during the day before Alipore court, which remanded them in police custody till September 21.
The arrested men, including main accused Munna Dhali, were Dipak's employees. While three of them were apprehended from Haridevpur and its adjacent area, one was arrested from Bishnupur area, he said.
Pachnanda said Munna, who used to deposit daily collections to Gouri Bhattacharya, had masterminded the crime.
On Thursday, he led the three others to the house at 11.30 AM and asked the domestic help to make tea.
They overpowered and killed her as she turned towards the kitchen.
Their next victim was Gouri Bhattacharya's attendant, whose body was found in another room. The four culprits then went upstairs and murdered Dipak and his mother, who was in another room.
The men, however, failed to unlock or break open lockers or locate money in any other place in the house. They made a hasty exit after a telephone rang in the house, the Police Commissioner said.