According to police, P Mohanan, CPI(M)'s Kozhikode district secretariat member, was taken into custody from Quilandy near here and was taken to the camp office of the Special Investigation Team (SIT) at Vatakara.
His wife K K Lathika is CPI(M) MLA from Meppayyur in Kozhikode district.
Mohanan is the first district level leader to be taken into custody by SIT, though several area, local and branch level CPI(M) activists have already been arrested in connection with the politically sensitive case.
Chandrasekharan, once a prominent CPI(M) functionary in the Communist stronghold Onjiyam near Vatakara, was hacked to death on May 4.
He left CPI(M) in 2008 over ideological and organisational issues with the leadership and floated a parallel outfit called Revolutionary Marxist Party.
Though the killing was done by a hit squad, police suspected that the murder was the result of a "conspiracy" hatched by some CPI(M) functionaries.
The party, however, has persistently rejected the charge.
Reacting to Mohanan's arrest, CPI(M) central committee member E P Jayarajan accused the police of acting in tune with the plan drew up by the Congress-led UDF government to frame the party.
"We have been saying this right from the start. With this, it has become all the more evident that the investigation is moving as scripted by party's enemies", Jayarajan said.
Chandrasekharan's widow, Rema, said the RMP's contention that the murder was plotted by the CPI(M) was getting vindicated day by day and the police taking Mohanan into custody was the latest evidence.
