Police said the accused confessed to killing the woman.
The woman, whose severed head was found at a garbage dump in south Kolkata's Tollygunge area, was allegedly killed by her brother-in-law as she had snubbed his advances, police said on Saturday.
Cracking the case within 24 hours, Kolkata Police arrested the brother-in-law, identified as Atiur Rahman Laskar, from his native village, Basuldanga, in Diamond Harbour in South 24 Parganas district.
Police claimed that Laskar, a construction worker, confessed to killing the woman who was separated from her husband two years ago.
While the severed head of the woman was found in a garbage dump near Graham Road on Friday, the torso and the lower portion of the body were found on Saturday beside a pond in the Regent Park area, DCP (South Suburban) Bidisha Kalita told a press conference.
The woman, who worked as a domestic help in the Regent Park area, used to commute to work every day along with her brother-in-law who also used to work in Tollygunge, she said.
Laskar wanted a relationship with her, and as she spurned his advances, he got furious, the DCP said.
"She started avoiding him a week back and it added to his rage. She also blocked his phone number. On Thursday evening, after she was done with work, he forced her to accompany him to an under-construction building. He strangulated her there and then beheaded her. He cut the body in three parts and dumped those," Kalita said.
"The woman was aged around 35-40. It is also being investigated if other people were involved," he said.
Police had earlier said that the woman was in a relationship with the accused, and a complication arising out of it led to the murder.
The discovery of the severed head had sent shockwaves in the middle-class neighbourhood in the southern part of the city.
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