A youth said to be in depression on Sunday slapped chief minister Bhupinder Singh Hooda while the latter was riding an open jeep in Panipat, reports Indian daily Hindustan Times.
The man was identified as 22-year-old medical representative Kamal Mukhija of Gohana, Sonepat.
The chief minister was in Panipat to preside over various official functions.
The incident that exposed the lax security arrangements took place near Sanjay Chowk.
Hooda was accompanied by Karnal MP Arvind Sharma and commandos from the Haryana police.
Later, various media organisations accessed a video recorded by an unidentified person. It could not be confirmed if the incident and its recording were planned.
The video shows a man wearing denims and a brown jacket, identified by the police as Mukhija, emerging suddenly from the crowd near the chief minister's vehicle and jumping to slap Hooda.
The police immediately overpowered Mukhija as an angry chief minister was seen instructing the policemen.
SP B Satheesh Balan told HT over phone that Mukhija was suffering from depression and was under medication. Denying that Hooda was slapped, the SP said Mukhija tried to jump near the CM.
"We have booked Mukhija for breaching the security cordon. Nothing incriminating was found from him. The accused pleaded that he crossed the security cover in excitement caused by sedatives prescribed for a patient of depression," said the SP, adding that the matter was being probed.