need help please

father passed away nov/07. i've been estranged from father for 3 years due to restraining order against my brother who lived with my dad. the only copy of will is in father's house (where brother resides). in this will i was to recieve the house. dad had put my name on the deed at the time he made out the will to save me taxes. 2 years ago my half-sisters brother inlaw (a disbarred lawyer) shows up asking me to sign off the house so my dad would be entitled to a grant for making his house wheelchair accessable, i signed.
i have heard nothing from anyone about the will which leaves me to believe that my brother had made a new will and forged my dads signature. i should say that last summer my dads friend told me that my brother had asked him how to get my name off the will.this brother owes years of child support, the mother of the child visited him last week to ask where the money is. he told her that his hands are tied and that i had put a lien on the house, which i have not.

is there anything i can do? it's bad enough that he has robbed me of seeing my dad in his final years, and now this.
i live in ontario, canada