The sheriff may maintain a confidential bank account in accordance with state regulations for use in undercover investigative drug enforcement operations.  Pursuant to T.C.A. § 39-17-420(a)(1), cash transactions related to undercover investigative operations of county drug enforcement programs shall be administered in compliance with procedures established by the comptroller of the treasury.  The comptroller’s guidelines, Procedures for Handling Cash Transactions Related to Undercover Investigative Operations of County and Municipal Drug Enforcement Programs, have the authority of law.  See also T.C.A. § 53-11-415.