Kochi, Jan 13 (Agencies): Two accused in the sister Abhaya murder case on Thursday filed petitions before a CBI special court here seeking their discharge from the offences arraigned against them.

Father Jose Puthrikayil and Sister Sephy, the second and third accused respectively, contended that the narco analysis test conducted on them by the CBI, was faulty.

CBI special court judge S Vijay kumar posted the case to March 20 for further hearing regarding framing of charges.

Abhaya was found dead under suspicious circumstances in the well of the St Pius convent at Kottayam where she was staying in 1992.

Police had earlier closed the case as suicide. But, the investigation was later handed over to CBI, which also filed two closure petitions but they were rejected by the Kerala high Court.

In 2008, Father Thomas Kottoor, Puthrikayil and Sephy were arrested on the charge of murdering Abhaya after detailed scientific tests, including narco and polygraph, were conducted on them.