The Delhi police on Sunday filed a complaint against the man who allegedly slapped Chief Minister Arvind Kejriwal during a roadshow a day ago, officials said.
The accused, Suresh, has been booked under the relevant sections of the Indian Penal Code, Deputy Commissioner of Police (West) Monika Bhardwaj said.
He was sent to two days of judicial custody, the police said.
The 33-year-old, who the police said was a disgruntled Aam Aadmi Party (AAP) supporter, allegedly slapped Mr Kejriwal during a roadshow in west Delhi's Moti Nagar on Saturday.
The chief minister was atop an open jeep when a man wearing a red T-shirt jumped onto the vehicle and slapped him before being pulled off the vehicle.
According to the police, Suresh, who is a scrap dealer in the area, had been an AAP supporter and used to work as an organiser of the party's rallies and meetings.
Suresh had said he had got disenchanted due to the behaviour of party leaders and he was angered further due to the party's "distrust in the armed forces", the police had said.
"The Delhi police is planting that the man belonged to the AAP. This is really shameful given the fact that the attacker's wife has herself said he was a Modi ''bhakt'' (ardent supporter) and did not like anyone talking against Modi," AAP spokesperson Saurabh Bharadwaj had said on Saturday.
Refuting the charge, a police spokesperson said Sunday: "The Delhi police is a professional force and levelling such allegations is incorrect. The force provides security to several political leaders in the utmost professional way."