Deputy Commissioner of Police (west) Vijay Kumar said the accused, Kuldeep Thakur, was arrested from his hideout in west Delhi today.
Thakur, who is a small-time property dealer, has over 20 cases of murder, extortion and attempt to murder pending against him.
"Thakur told police that she was cheating on him and was having relationship with some other men as well. He claims he killed her following an argument over the issue," the officer added.
The naked body of the 39-year-old woman was found at her rented apartment in west Delhi's Vikaspuri Extension near Tilak Nagar last week.
There were multiple injuries on the body and it was suspected that the woman, who used to run a coaching centre for students preparing for competitive exams, had been smothered to death.
During investigation, it was found that her live-in partner - Thakur - was missing since the incident.
Several raids were conducted across Delhi before police could arrest him.
The couple was living together for the last couple of years. The victim had taken divorce from her husband and got into a relationship with Thakur.
The couple also had a secret wedding at a temple, however, they were not legally married, sources said.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
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