A special court of the Central Bureau of Investigation on Wednesday sentenced to life imprisonment the catholic nun and priest, who were found guilty of killing 21-year-old Sister Abhaya in 1992 at Kottayam.

Special CBI judge K. Sanal Kumar pronounced the sentence and slapped a fine of Rs 5 lakh each on the two accused -- Father Thomas Kottoor and Sister Sephy.

The court had on Tuesday found the two guilty of the murder of Sister Abhaya, who was found dead in a well in St Pius convent in Kottayam in 1992.

The case, involving the brutal murder of the 19-year-old Sister Abhaya after she saw two priests in a compromising position with a nun in a convent in 1992, witnessed many twists and turns as witnesses turned hostile and multiple investigative agencies wrote it off as a suicide, provoking protests.

The local police, crime branch and the CBI had filed closure reports before a court ordered a reinvestigation in 2008.

The duo was also sentenced to seven years imprisonment for tampering with evidence.

The two sentences will run concurrently.

Massive protests had erupted in Kerala after Sister Abhaya’s death after the local police and the crime branch wrote off the case as “death by suicide.” The CBI, too, had filed closure reports in 1993, 1999 and 2005, unable to decide whether it was a suicide or murder.

The central agency made the arrests after the court ordered it to reopen the investigation.