The Kozhikode special additional sessions court in January this year, while sentencing 11 of the 12 accused to life in the murder case, let off the 24 people.
Subsequently, the Kerala government filed an appeal pointing out that vital information, including evidences, was produced before the lower court against the exonerated people but this was overlooked.
TP Chandrasekharan was hacked 51 times by assailants on May 4, 2012
The division bench of Justice K. Vinod Chandran directed notices to be served to all 24 who have been let off.
Chandrasekheran, 51, who launched the Revolutionary Marxist Party, was hacked 51 times by assailants May 4, 2012, when he was returning home on his motorcycle.
A hugely popular leader in and around the Kozhikode district, Chandrasekheran took on his former party CPI-M, from which he was ousted in 2008.
He flayed their ideological stand that provoked CPI-M state secretary Pinarayi Vijayan to publicly declare Chandrasekheran "a renegade".
The 24 people exonerated include P. Mohanan, husband of CPI-M legislator K.K. Lathika.