My brother dies,i have his power of attorny.i sold his all property.now my step brothers claim for those prpty?

my brother lived abroad.he had no child.he gave his power of attorney.he died 10 years before.his property authorised under me for about 25 years.for my need i sold all his property.now our step brothers claiming me for distributing those property.or they will take me under law what to do.