The couple stayed at the servant quarters of parliamentarians' flats in South Avenue. (Representational)

A married woman and her lover have been arrested for allegedly hiring killers for Rs 7,000 to murder her husband at the couple's accommodation in Delhi's South Avenue, police said on Saturday.

A juvenile has also been detained for the murder of 52-year-old Suresh Kumar whose throat was slit when he was alone at his home on June 7. However, his accomplice, identified as Aman, is missing since the incident.

Suresh Kumar's wife Anju and 21-year-old Shivam Thakur have been arrested in the matter. Aman was Shivam Thakur's friend and allegedly hired for killing Suresh Kumar.

The couple stayed at the servant quarters of parliamentarians' flats in South Avenue.

According to police, Suresh Kumar did not share good relations with his wife - who was 16 years younger to him - and indulged in gambling.

On the night of the incident, one of the residents had seen two masked men fleeing from the area.

During investigation, the police learnt that Anju used to often visit her family and friends in Meerut without her husband. This raised suspicion about her involvement and the police zeroed in on Shivam Thakur, her relative and partner, Deputy Commissioner of Police (New Delhi) Madhur Verma said.

Shivam Thakur was arrested from a relative's house in north Delhi's Burari, he said. Probe revealed that he had developed closeness with Anju, who is related to him.

"Anju disclosed that she was not happy with her conjugal life. Her husband indulged in gambling at home and several people came to her house, to which she objected. He forced her to make tea and food for them at odd hours," the officer added.

A month before the incident, Anju had even consumed poison after a fight with her husband. When Shivam Thakur asked her the reason, she insisted that either she or her husband should die. So, Shivam Thakur along with Anju planned to kill Suresh Kumar, the DCP said.

Shivam Thakur involved his friend Aman, a resident of Meerut, in the conspiracy. Anju promised to pay him Rs 7,000 for the crime, he said.

Aman and his juvenile accomplice left for Delhi. Suresh Kumar was sleeping alone at his home when the juvenile and Aman allegedly slit his throat, the DCP said. Suresh Kumar's wife had claimed that she and her children were out for a walk at Teen Murti Marg when it happened.

Suresh Thakur was employed at a medical store in Meerut while Anju was working as a domestic help in MPs' flats at South Avenue, police said.