Should there be a supervisor, such as the Reserve Bank of India that looks into the loan activities of informal lenders? Why would its task be quite difficult?

There must be a supervisor for checking the loan activities of informal lenders such as the Reserve Bank of India supervises other banks. The task would be quite difficult because informal sector includes several people who have their variety of business besides lending and the most important part to be noticed about these sectors are that they are not registered with the government and without registration there is a risk of fraud of any kind of mishappening with borrowers as well as with lenders of loan.