Thanks Bob for your invaluable suggestion.

For the visitor visa the sponsor has to say that s/he is willing to bear all the cost for the duration of stay of the potential visitor. I have sponsored student visa for my uncle's son but he is a very dilligent guy who is working on his bachelors with no intention of doing anything wrong. In case of my elder brother, he has family back home so just wants to work here for several years save as much as he can and go back. That's all fine, I have no problem with that. Actually I will be very happy if he can do that. But I should not put myself in trouble as well.