A financial institution shall keep a record of currency transactions in excess of $10,000 and shall file with the Department within 15 days of the date of the transaction pursuant to regulations adopted by the Secretary a complete report of currency transactions in excess of $10,000. The reporting requirements of this section are complied with if: A financial institution files with the Department a duplicate copy of the report required by 31 U.S.C. § 5313; or The information in the report required by 31 U.S.C. § 5313 is available to the Department from a federal agency. The Secretary shall adopt regulations to carry out the purposes of this subtitle and to provide for the exemption of transactions which are clearly of a legitimate nature and for which mandatory reporting would serve no useful purpose. A transaction that is exempt from reporting by a financial institution under federal law is also exempt from the reporting requirements of this subtitle.