Brother misused my power of attorney and sold the property to someone

My brother misused my POA and added his name and sold my property to his wife relative . his relative did not have money so he said no problem I will help u to buy the plot but must give me the bunglow construction and then pay for the plot so before I gave his general poa he signed the plot and construction agreement and his relative paid me only 1lakh 40k as official money rest all he paid my brother as per the legal docoument I am the 90% and he is the 10% property owner but I paid 100% of the value for the property and have the proof he had kept all the original document with him as I am an NRI he took the advantage and did a agreement before I gave his poa for the plot and the house secondly the chequed issued on the contract is issued as posted dated later x'lled after one year and the same chq issued for construction agreement I did not have any proof as my brother had kept all the original document in his custody its been 11 year since I am trying to dig the truth