The Central Bureau of Investigation (CBI) will file an appeal before the Calcutta High Court (HC), seeking death sentence for Sanjoy Roy, who was sentenced to "life imprisonment until death" by a Sealdah court in the Kolkata rape-murder case, officials said Wednesday, two days after the judgment.

According to news agency PTI, CBI received a legal advice suggesting that the case may be categorised as the "rarest of rare", deserving capital punishment, they said.