Thiruvananthapuram: The trial of the controversial Sister Abhaya case began on Monday in Kerala's Thiruvananthapuram special CBI court. Abhaya, a nun of Pious X convent in Kottayam, was found dead in a well on the premises of the convent on March 27, 1992.

It was initially thought to be a case of suicide by the CBI later concluded that it was murder. The probe agency had charge-sheeted Catholic priest Thomas Kottoor and Sister Stefi. They were charged with murder, destruction of evidence, criminal conspiracy and other charges in 2008. Another accused, Father Jose Poothrukayil, was let off by the CBI court last year after it found there was no evidence against him.

Also read: Sister Abhaya murder case: High court tells priest, nun to face trial

The initial day of the trial appeared to go against the prosecution. Three witnesses were summoned for examination. Among the three, two have died. The CBI had named a nun as a witness. She let the agency down by throwing her lot in with the defence.

The nun withdrew her statement that she had seen Sister Abhaya's headscarf and a pair of slippers near the well where her body was found the next day. She also denied she had heard the sound of something heavy falling into the well the previous night.

According to the CBI charge sheet, Sister Abhaya woke up early to study and went into the kitchen to wash her face. She reportedly witnessed two priests and a nun in a compromising position and was killed fearing that she might reveal what she saw to others.

The agency said she was first attacked with an axe and later dumped in the well. Though the sensational case created enough ripples in the state, the church stood by the accused saying they were innocent.