My brother was cheated by his friend around 30 lakhs in the name of friendship

My brother gave around 30 lakhs to his friend , he told that he will give share in his company and cheated by his friend , whenever he requires money he used to ask my brother for his needs and he used my brothers debit and credit cards in the name of friendship by giving oral promises that he will repay it whenever he gets his company bills. around 13 lakhs he urged by brother to apply personal loan from axis and hdfc banks and used all those money for his personal needs like buying clothes in malls , for long drive cars, for staying in hotels with his girl friends through my brothers debit card itself . And whenever my brother asks money he used to give fake promises on phone calls. and he used 6 credit cards of my brother. he very intelligently used all debit and credit cards in the name of my brother only . now he cheated and went to dubai . my brother is suffering a lot by paying the loan amount EMI'S and credit card EMI'S . we informed his parents ,his father in return went to police station and gave complaint on my father that we were blackmailing him by taking money from him by non repayment to him. that fellow didn't left us any evidence, he intelligently used all money in the name of my brother only . can you please give us any suggestions how to file case as there was on audio recordings and some what's app chats as evidence , he used threaten my brother whenever he asks money . there was no evidence expect some of the transactions were done on his name around 5 lakhs on different dates. please provide legal advice how to solve this problem .