The Crime Branch would probe the case relating to the arrest of a 75-year-old man with an airgun and sword near the residence of CPI-M state secretary Pinarayi Vijayan in Kannur district on Thursday, official sources said.
The CPI-M state secretariat had demanded a detailed probe into the incident, saying in a statement that the incident should not be taken lightly by portraying the person involved as mentally imbalanced.
CPI-M claim the incident was an attempt on Vijayan's life.
Home Minister Thiruvanchoor Radhakrishnan has given instructions to hand over the probe to the Crime Branch, the sources said.
The man, identified as one Kunhikrishnan Nambiar from Valayam in Kozhikode district, was arrested after local people informed them that he was moving near Vijayan's house in a suspicious manner on Thursday.
He has been remanded to judicial custody by the Judicial First Class Magistrate, Thalassery.