So sorry for your loss, Tatiana. I concur with other posters about not letting your uncle get away with this fraud. Unless he can produce a will that will stand up in court, it would seem that a child (like maybe, you) would be considered the legal next-of-kin and would have precedence over a brother in deciding what to do with the deceased's things. You definitely need to consult a lawyer. Given what you said has already happened, it is a good bet that this uncle of yours will either abscond with any money and insurance payouts himself or give it all to the Society. If he can't or won't produce a valid will, please don't let him get away with it.
Just my 2 cents worth...