Society wrongly wanting to recover 1lac for lift repair from member

There was recently a fire hydrant repair carried on in the society my father lives in. After that due to dirt outside my father's flat, he swept the area with a dry broom. Next day society says lift is not working and my dad has to pay for it (1lac). Background - my dad was the society secretary for many years before and the current society managing committee members harbour a lot of grudges against him. He had sent a picture of the dirt on the society watsap group saying that the fire hydrant repair people left the place dirty and he had to "physically clean it". He never used any water and he had verbally confirmed this to the committee member. These committe people have also gotten the lift repair person to write that the seepage is from the same floor as the one my father lives on. But there is no flat number written on the report. However the lift which is close to my father's flat was spoiled. Now these committee members are trying to force my father to pay 1lac for the lift saying he has used water and he is lying . They are harassing him by sending multiple letters to the flat and they are not accepting or acknowledgijg his reply letters. We had a meeting where my father in person clarified his side as well still they are not ready to believe him. They were very aggressive towards him during tht meeting as well. My dad is a senior citizen with BP issues and he is very stressed over what can be done. Pls help