Anita, however, came under suspicion after she tried to mislead the police (Representational)

A 25-year-old woman, her brother and a relative were arrested in connection with the killing of her live-in-partner in south east Delhi's Amar Colony area last week, police said on Wednesday.

Anita and her live-in partner Sunil Tamang, 28, used to stay in a rented apartment in Amar Colony area of the national capital. Sunil, who hailed from Nepal, worked as a waiter at a restaurant in Saket, they said.

The woman had earlier told police that she had gone to meet her friend in Greater Noida at 11.30 pm on September 9. When she returned the next day around 2 pm, she found Sunil Tamang's body on the floor, Deputy Commissioner of Police (Southeast) Chinmoy Biswal said.

Anita, however, came under suspicion after she tried to mislead the police and failed to give satisfactory reply about her visit to Greater Noida on the night of the incident, the officer said.

Later, she confessed to police that her brother, Bijay Chhetri, 30 and relative Rajender Chhetri, 30 had killed her partner. A team was sent to West Bengal and on September 13, Bijay and Rajender were nabbed from a village in Kalimpong, the DCP said.

During interrogation, Bijay disclosed that his sister Anita was already married, but because of a dispute with her husband, she had left him and started living with Sunil, Mr Biswal said.

For a few days before Sunil Tamang's death, Anita and her live-in partner were fighting constantly, the officer said, adding Bijay Chhetri also claimed that at times Anita was deprived of basic needs by her partner.

Anita wanted to leave Sunil but he was against it. Thus, Bijay hatched a plan with Anita to kill Sunil. He also roped in their relative Rajender to execute the plan, the DCP added.

Bijay and Rajender arrived in Delhi on September 7 and stayed in a hotel in Paharganj for two nights. On September 9 at about 10 pm, they arrived at Sunil's rented accommodation and stayed there for the night, he said.

As per plan, Anita handed over a knife to Rajender and left for her friend's house at Greater Noida. At about 4 am, when Sunil was asleep, Bijay and Rajender killed him, left the house in the morning and boarded a train for West Bengal from Anand Vihar Railway Station, the police said.

On the way to the railway station, they threw the knife at Ring Road area which has been recovered, police said.