Officials said the Returning Officer of Bhangar seat in South 24 Parganas filed the FIR against Mollah under section 509 of the Indian Penal Code (word, gesture or act intended to insult the modesty of a woman).
A show cause notice was yesterday issued against him from the Election Commission (EC) for making derogatory remarks against Ganguly.
Mollah replied, but the officer was not satisfied with his reply after which the FIR was filed, officials said.
He had been showcaused on an earlier occasion too and was even issued a censure by the poll panel for violating the Model Code of Conduct.