Blank a4 signed & given to advocate

Dear Sir, During my visit to my hometown in UP, I hv to sign blank A4 sheets of paper & give it to a local advocate for filing an affidavit & application to court for enrollment of my name in the property as my father has passed away. (In UP I have ancesteral property house jointly in the name of my father & his brothers). Can these blank signed A4 white papersbe used against me.?? I asked the lawyer to return those papers, he has told me that they are destroyed. PL advise. Thanks Kumar N