Kollam: A 55-year-old nun was found dead on Sunday inside a well at the Mount Tabor Dayara Convent in Pathanapuram, more than 75km from state capital Thiruvananthapuram, police said.

The body of Sister Susan, who taught at St Stephens School attached to the convent, was found floating in the well at the sprawling compound in the morning.

A senior police officer told PTI the body had "self-inflicted" injuries on both hands. "There were self-inflicted injuries on her wrists. The left cut was more severe and deep. The injury on the right wrist was comparatively small," the officer said. He said more details would be available after the post-mortem report comes in.

The nun belonged to the Malankara Syrian Orthodox Church.

Other inmates of the convent first came across bloodstains near the well and then found her body floating around 9am. Bloodstains were also found inside her room, nearly 50 metres from the well.

Police and fire department personnel pulled the body out and carried out an inquest at the scene. A case of unnatural death was registered and the body sent for post-mortem to the Government Medical College in Thiruvananthapuram, the officer said.

The police had earlier examined the nun's room and other premises of the convent and recorded the statements of the inmates. Local TV channels quoted the inmates as saying the nun had been depressed for some time, but police did not confirm the claim.

Kollam district Congress president Bindhu Krishna has demanded an impartial probe.

The death of another Catholic nun, Sister Abhaya, under similar circumstances, had triggered a controversy in the state two decades ago.

Abhaya's body was found in the well of St Pius Convent in Kottayam on March 27, 1992. She was an inmate of the convent. Local police and the state crime branch had initially investigated the case and concluded that Abhaya had committed suicide. However, the case was taken over by the CBI on March 29, 1993.

In 2008, the agency had arrested two priests - Fr Thomas Kottoor and Fr Jose Poothrikkayil - and a nun, Sister Sephy, on the charge of murder.

According to the prosecution, Kottoor and Poothrikkayil allegedly had an illicit relationship with Sephy, also an inmate of the convent. On the night of March 27, 1992, Abhaya allegedly saw Kottoor and Sephy in a compromising position, following which the three accused hacked her to death with an axe and threw her body into the well, the CBI had said in its chargesheet. The accused were arrested in 2008 and released on bail by Kerala High Court a year later.