According to Jailor RB Yadav, as per orders of the Allahabad High Court, she was released from the prison at 7.20 pm.
In July, Ms Talwar had pleaded before the High Court for parole as her ailing mother needed medical attention.
The court had accepted her plea on August 29 and granted her three weeks' parole.
For the last few days, the paperwork related to her parole was going on.
The order for her parole was today sent to the prison authorities after completion of formalities.
In May 2008, 14-year-old Aarushi and the domestic help of the Talwars household, Hemraj (45), were found murdered at their residence in Noida.
A court in Uttar Pradesh subsequently held Nupur and her husband Rajesh Talwar, both dentists, guilty in the double murder case and sentenced them to life imprisonment.
They have been in jail since 2013.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)