Need your suggestion what to do now?

Hello! I am a student I live in a flat with 4 room mates. My one room mate (oldest) lost his 10,000rs which he had kept inside his bag's chain about a month ago (as told by him) according to him he had checked it till last Thursday (23rd april) the money was still there, but when he checked it after 3-4 days the money was not there, and directly or indirectly he suspects all his room mates (including me) that we might have stolen it, and he is now threatening to file case on us. But I haven't done it he knows it very well and am quite sure that the rest of the 3 also haven't done it. But as he is not sure who did it he is going to complain for all of us. He is also threatening that police is going to beat us all but as am innocent why would I get beaten. And also there is no proof that he had kept his money there, means all of us were unknown of this fact. Also to add his relation with all of us is like brothers, whenever anyone of us needed help he was always there to help us, same in case of money, he never hesitated to give us money whenever we needed it so how can he think that any one of us could steal it..? What are the legal actions can he take on this, and as am innocent what do I have to do..? Please enlighten me what to do now! P.s- I am not sure which area of law I should opt so I am choosing random.