The matter was reported around 7 PM yesterday when the constable, identified as Anil Kumar (21), was on duty, said a senior police official.
The constable had allegedly been stalking the woman for around the past five days. The woman had reported the matter to her parents on Monday and they decided to approach the police if the constable was seen following her again.
Yesterday, when the woman was walking home after attending coaching classes, the constable approached her and allegedly asked for her mobile number. The woman refused him and narrated the incident to her parents as soon as she reached home.
"The police later registered a case under relevant sections of the law, based on the woman's complaint, and the constable was arrested," said the official.
The woman is a second year student pursuing a degree in commerce from the School of Open Learning under the University of Delhi. She attends coaching classes in the evening and usually takes the same route towards home every day, the official added.