A case for allegedly "promoting enmity between different groups'' was registered against Aligarh Muslim University alumnus Sharjeel Usmani in Pune on Tuesday over his speech at the recent Elgar Parishad conclave.
The opposition BJP in Maharashtra had demanded action against Mr Usmani, accusing him of "hurting religious sentiments".
A case under section 153 (A) of the IPC (promoting enmity between different groups on the ground religion, etc) was registered against him, said Pune police commissioner Amitabh Gupta.
Pradip Gavade, a local leader of the Bharatiya Janata Yuva Morcha, BJP's youth wing, had filed a complaint with Swargate police station against Usmani, he said.
Further investigation is on, Mr Gupta added. The Elgar Parishad conclave took place in the city on January 30.
The gathering was also addressed by writer Arundhati Roy, Justice (retd) B G Kolse Patil and former IPS official S M Mushrif, among others.
Three years ago, several Left-leaning activists were arrested by the police for alleged Maoist links after the December 2017 Elgar Parishad conclave and the caste violence at Bhima Koregaon war memorial the next day.
Earlier in the day, BJP leader Devendra Fadnavis had demanded action against Sharjeel Usmani, alleging that he "insulted sentiments of the Hindu community".