A 42-year-old nun was found dead on Friday in a well of a convent in Kerala's Kollam district.
The police, after initial probe, said that the nun, identified as Mabel Joseph, is suspected to have died by suicide.
The inmates of the St Joseph Convent had launched a search for her after she didn't turn up for the morning prayers, police said.
A letter was found in her room in which she had allegedly written about her physical difficulties and that her body would be found in the well, police said.
The exact cause of death will be ascertained after autopsy.
A case of unnatural death has been filed.
Investigation is underway.