She was rescued yesterday after neighbours alerted the police and admitted to a hospital.
The teenager had been living in the flat that was kept locked from inside.
She was surviving on two meals a day and sleeping on a sofa surrounded by garbage in a second-floor, two-room flat.
After she was rescued and admitted to the LBS Hospital in Mayur Vihar, she claimed that she had voluntarily confined herself in the house.
However, the neighbours alleged that she had been forcibly confined by her mother. Her mother, aged 44, is fighting a maintenance case against her husband in a Karkardooma court, police said.
The couple has two daughters.
The elder daughter, who is 22-year-old, lives with her mother in a rented flat in Pandav Nagar.
When the neighbours heard the girl crying yesterday, they grew suspicious and called the police.
The girl was found sitting on a sofa, barely able to speak. She was taken to the Lal Bahadur Shahtri (LBS) Hospital, after which she was counselled by members from the Child Welfare Committee (CWC).
The police have claimed that the girl has not levelled any allegations against the mother.
The girl was initially hesitant to step out and didn't yield to requests by the police personnel but later relented.
Since no complaint has been received, police were yet to take any action in the case.
Police said that they would initiate further action on the direction of the CWC.
The girl's father claimed that after divorce, he was never allowed to meet his children. His wife had filed a case for maintenance against him in 2011 in the Karkardooma court.
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