The Central Reserve Police Force head constable has told the police that he was drunk.
The police said he had climbed on the platform, smashed the statue's head off and placed it near a traffic roundabout. He was traced with help of a CCTV camera installed nearby.
A CRPF statement later said the head constable has been under treatment at its Hyderabad facility for schizophrenia for a little over a month. He had gone on leave last week.
"The individual has been placed under suspension pending enquiry in the case," the statement said.
The vandalism came against the backdrop of senior BJP leader H Raja's controversial Facebook post after Russian communist revolutionary Vladimir Lenin's statue was pulled down in Tripura.
Mr Raja had warned that Periyar's statue would also be brought down but deleted the post following a massive outrage in Tamil Nadu. Soon enough, one Periyar statue was vandalised in Vellore. Two men were arrested in this case.
In Tirunelveli district, the police have prohibited large groups from gathering in the district after minority, Tamil groups and political parties such as the opposition DMK asked police to stop the yatra.
MK Stalin, DMK working president said "the crowd of cowards who are trying to enter Tamil Nadu through the rear entrance are miscalculating that by destroying Periyar's statue, his ideology could also be struck off."
Joining the voices opposing the VHP-led Ram Rajya Rath Yatra, superstar Rajinikanth, 67, had also attacked the AIADMK government for allowing the procession "with a divisive political agenda" was being allowed into the state.
"Tamil Nadu is a secular place and we must spare no effort to ensure communal harmony," he said.