Black ink was thrown at Aam Aadmi Party MLA Somnath Bharti on January 11 in Raebareli.
Bharti was headed to inspect government schools in the district when the attack took place.
An FIR has also been registered against Somnath Bharti in Amethi for his alleged derogatory statement about the condition of hospitals in Uttar Pradesh.
The alleged right-wing activist was upset with Bharti's remark and also lashed abuses at him.
Bharti also got involved in a heated argument with police officials when an alleged right-wing activist threw ink on him.
After the incident, Bharti was detained in the guest house itself.
The youth who threw ink on Bharti managed to escape.
