Any person who willfully testifies falsely as to any material matter in an investigation or proceeding under this section shall be guilty of perjury. Banks, employers, insurers, savings banks, savings and loan associations, brokers, and fiduciaries, upon request of the department, shall furnish in writing and duly certified, full information regarding the property, earnings, or income or any funds deposited to the credit of or owing to any person liable under sub. (2). That certified statement shall be admissible in evidence in any action or proceeding to compel payment under this section, and shall be evidence of the facts stated in the certified statement, if a copy of the statement is served upon the party sought to be charged not less than 3 days before the hearing.