y nt revealing karan's truth??

they are always saying sb is hurt bcoz no mother wants her son to be like dat. but why cvs didnt reveal dat karan was not sb's real son? i thought dat aftr karan death during investigation of case they would show dat he was nt her real son but nothing happen like that. still vadhera's believe dat how bad karan was but he was sb's son.
I think this has to be reveal anyway dat he was not her real son.