If any person in possession of books, vouchers or papers relative to public accounts before the controller shall refuse to produce the same, or if any officer whose accounts are to be settled and adjusted by the controller shall refuse to attend or submit to examination, the controller shall proceed, by the examination of witnesses and other evidence, to ascertain and settle, as near as may be, the amount of public money received by such officer and its application to public purposes or otherwise.
16 P.S. § 4929