Justice Aruna Jagadeesan set aside the judgement by a lower court given in February of last year and acquitted all the policemen after observing that the charge against them had not been proved. The lower court had sentenced the policemen to up to 10 years' rigorous imprisonment.
Karuppi, a domestic help, was accused by her employer of stealing a gold chain from his house.
She was questioned at Parmakdui police station where she was allegedly tortured for six days. Her body was found hanging from a transmission tower behind the police station in the early hours of December 1, 2002.
But various organisations took up the case and the policemen were convicted by the lower court in February, 2013.