Natarajan and his brother M Swaminathan have been booked under the Public Nuisance Act and IPC for violating Police orders while participating in the Mullivaaikal memorial inauguration conference from November 8 to 10.
The memorial built in Thanjavur for Tamil martyrs of the war in Sri Lanka was inaugurated last week.
Natarajan submitted that he was among those named accused in the case for allegedly violating the 10 PM deadline stipulated by police for use of loudspeakers.
Swaminathan said he had gone to the function only as a spectator, and he was innocent.