• Running a carpenter shop at home

Dear Sir,

My parents are old (in their late sixties) and live in their individual house owned by my father. He is basically a carpenter and has been running his business in a rented shop for many years. Since he is old now, he has shifted his work to a small room in his own house and has been doing this for past few years. Although I support him financially, my parents still feel they do not want to be completely dependent on their children and so he is still continuing his carpentry work. This also keeps him occupied. In order to ensure the neighbors don't complain, he works only during daytime (9 to 5) and avoids working during weekends and holidays. So far we haven't had any issues with the neighbors and things went well. Last year we had a new neighbor (who bought the house next to my parent's house) and initially everything was fine. But later they started complaining that my father's work is disturbing them. We spoke to them and tried to resolve the issue. They went ahead and complained to the police not once but thrice. The police began to mediate and were trying to settle this amicably. After a few more complaints, the police also began to understand that the neighbors only plan is to harass my parents and they are not taking it seriously anymore. Enraged, the neighbor has complained to the Commissioner of Police and since the complaint came back to the same police station, the policemen knew what the issue was. My father also gave in writing his situation. Now as a last resort, the neighbor has gone and complained to the Corporation saying my father is running an industry at home without proper licenses. 
Kindly advice as to what we should do to avoid such a harassment when my parents means to livelihood is being disrupted. They have been living in that house for more than 25 years and all other neighbors know them to be peaceful and friendly.