Police on Wednesday initiated a preliminary investigation into a complaint by a nun, who has accused a Roman Catholic Bishop of raping her, claiming that she had received death threats on phone from unknown persons.

In her complaint filed at Kuravilangad police station, the nun has claimed that she had received death threats on phone from the unknown persons two months ago, police said.

A preliminary probe has been launched on the basis of her complaint, police said.

Further steps would be taken after examining the call records, they said.

Earlier, the nun had lodged a complaint with Kottayam district police, accusing Jalandhar Bishop Franco Mulakkal of raping and having unnatural sex with her multiple times between 2014 and 2016.

A special team probing the case has said as per the initial investigation of the police, Mulakkal abused his position and repeatedly raped the nun.

Responding to a petition seeking speedy investigation, Deputy Superintendent of Police, Kottayam, K Subhash had informed the Kerala High Court on August 13 that the probe was proceeding effectively and impartially.

The police, in a statement prepared based on initial investigation and available evidence, had said it was revealed that the Bishop committed unnatural offence and committed rape repeatedly on the nun against her will.

The bishop confined the nun to a guest room in St Francis Mission Home in Kuravilangad in Kottayam district of Kerala, the statement had said.