According to police, the gardener lives in Sultanpur area in the vicinity of the victim's house and was friends with her.
"Her proximity with some other men irked him following which he along with some of his associates allegedly picked her up, gangraped her and then killed her. The body was dumped in the nursery. He has been arrested and efforts are on to nab his associates," said a police official.
On Sunday, 2 people were detained in this connection.
The victim who was missing since Friday evening was brutally gangraped by the assailants and a wooden stick was inserted in her private parts.
The body was found in a Delhi Development Authority nursery in south Delhi's Vasant Kunj area.
The incident came to light on Saturday around 8:20 am when a security guard informed the police about the body which he had spotted lying in bushes.
The semi-naked body of the woman with hands and legs tied was found in the bushes of the nursery.
On Sunday, scores of students from Jawaharlal Nehru University had staged a protest outside Vasant Kunj police station in south Delhi over alleged police inaction in the case.
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