PIERRE, S.D.(KELO)- The South Dakota legislature is moving forward with a subpoena as it investigates several fraud cases in the state Revenue Department.

The Legislature’s Executive Board voted unanimously in favor of seeking the subpoena, to compel testimony from Revenue Secretary Mike Howdyshell.

Executive Board Chair Lee Schoenbeck says the rule that prevented Howdyshell from testifying should not be allowed to interfere with the legislature’s investigation.

The legislature’s Government Operations and Audit Committee says it needs the testimony to see what went wrong, and to develop policy from preventing fraud in the future.