Former Commonwealth Games chief Suresh Kalmadi, DMK MP Kanimozhi and former communications minister A Raja were among the thousands who celebrated Independence Day at the Tihar Jail on Monday.
"Kalmadi, Kanimozhi and Raja joined the celebrations with other inmates," said prison spokesperson Sunil Gupta. "Pakistani prisoners and other foreign nationals too celebrated the day."
Around 50 prisoners, facing minor offences, were released on the day for their good conduct.
Remission of prison terms for around 2,000 inmates was also announced.
Director General Neeraj Kumar addressed the prisoners, jail staff and security forces at the flag hoisting function.
Special food was provided to all prisoners, who sang patriotic songs and performed dances to mark the occasion.