CPI(M) Kannur district secretariat member Karayi Rajan and party youth wing SFI Kannur district secretary Sarin Sasi were among those let off.
Defence counsel had argued that 24 accused in the case should be freed citing lack of evidence. Barring four, all the other accused were let off.
Initially, the special team probing the murder case had chargesheeted 76 persons. However, 57 persons faced trial in the court. Earlier, the trial court discharged two persons as there were no sufficient material to proceed against them.
Two others were absconding in the case and the Kerala High Court in January stayed trial proceedings against 15 accused.
Chandrasekharan, who quit the CPI(M) a few years ago, had floated the RMP. He was murdered by a seven-member gang at Vallikkad near Onchiyam in Kozhikode district on May 4 last year.