An Indian court awarded a life sentence on Monday to a police volunteer convicted of the rape and murder of a junior doctor at the hospital where she worked in the eastern city of Kolkata, rejecting demands for the death penalty and saying it was not a rare crime.

The CBI will file an appeal before the Calcutta High Court, seeking death sentence for Sanjay Roy, who was sentenced to "life imprisonment until death" by a Sealdah court in

An Indian court on Monday sentenced a police volunteer to life imprisonment for the rape and murder of an on-duty doctor last year – a crime that sparked nationwide protests. Sanjay Roy, 33, plans to appeal the judgment in a higher court.

India's West Bengal state launched an appeal on Tuesday to overturn a life sentence in favour of the death penalty for a police volunteer convicted of the rape and murder of a junior doctor, a senior lawyer aware of the development said.

The Sealdah court rejected CBI's plea seeking death penalty for Roy, saying the crime did not fall under the "rarest of the rare" category.

Chief Minister Mamata Banerjee-led West Bengal government had filed a plea challenging the life imprisonment sentence handed to Sanjay Roy, sole accused in RG Kar rape-murder case.