Space taken forcefully by neighbor

I have an underconstructed house at my native which falls in a gaoton ruled by grampanchayat. To my surprise one fine day I got to know that my neighbor have constructed a toilet for his personal use but beyond the permissible boundary from his wall i.e.5 feet. As per my knowledge I understand that every villager has to maintain 3 feet distance from their respective boundary wall for other purposes. My neighbor without taking anyone's concern and without any mutual discussion with us fearlessly built it and started using it as well. Now in future if I plan to do plaster work for my unfinished house it would be difficult on one side of my wall as there is hardly any space left for anybody to stand to do any working. For this inconvenience I approached the sarpanch and gramsevak and wrote a written complaint against my neighbor, in return they have asked me to prove whether the space acquired by the neighbor does it belongs to me if so only then they will take action against my neighbor and not before that. I don't understand what to do. Please advise.