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.

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.

A sessions court in Kolkata will pronounce today the quantum of sentence for Sanjay Roy. Follow The Hindu’s live updates

A Kolkata court on Monday criticised the authorities at the RG Kar Medical College and Hospital and the police for attempting to cover up the murder of a junior doctor as a suicide, Live Law reported.

An Indian court has sentenced the man convicted of raping and murdering a female doctor at a Kolkata hospital to life in prison.

The BJP on Monday criticised the sentence of life imprisonment for the convict in the RG Kar rape-murder case by a Kolkata court as a "travesty of justice", and said justice must not only be done but also be seen to be done.

The court found the former Kolkata Police civic volunteer guilty last Saturday. Judge Monday informed Roy he can appeal before HC against the sentencing. Roy maintains he is innocent.

The police had sought the death penalty in a horrific but familiar crime. Its handling by the local authorities had outraged the nation.