The first-floor flat of the Senguptas. Picture by Sanjoy Chattopadhyaya

Manju Sengupta, 66, was strangled and burnt in her New Ballygunge flat at Kasba early on Monday, allegedly by her son and daughter-in-law.

Parthasarathi Sengupta, a journalist, and his wife Barnali were arrested later on Monday on murder charges under Section 302 of the Indian Penal Code.

According to police, around 6.30am, domestic help Kali stumbled upon Manju’s body, charred almost beyond recognition, in the parking lot of the building.

She raised an alarm and the neighbours gathered at the first-floor flat of the Senguptas, where Manju lived with her son, his wife and their five-year-old daughter.

“We kept banging on the door till Parthasarathi finally opened the door. We demanded to know where his mother was. He went into a bedroom as if to look for her and then emerged to say she was not at home and might have gone out somewhere,” said next-door neighbour Aloke Das.

Residents of the area, who alleged that Parthasarathi used to “torture his mother” over money matters, then dragged him out and beat him up. Police intervention and the deployment of the Rapid Action Force stopped things from spinning out of control.

The police found a kerosene jerrycan, a match box and a torch in the parking lot near the body. Blood stains were visible on the steps leading to the car park from the first-floor flat.

Preliminary investigation suggested that Manju was first strangulated, causing bleeding from the mouth. Then her body was set ablaze. After that her body was dragged from the flat to the parking lot.

Around noon, officers from the Criminal Investigation Department (CID) visited the house to collect samples.

Praveen Kumar, the district superintendent of police (South 24-Parganas), later said the couple had been arrested and would be produced in the Alipore court on Tuesday.