Haw. Rev. Stat. § 236E-25
When receipt of estate tax information from the Internal Revenue Service under section 6103(d) of the Internal Revenue Code discloses possible Hawaii estate tax liability, any person possessing federal estate tax information shall be required to submit the information to the department upon request to enable the department to audit the return or Internal Revenue Service audit adjustments and to determine whether any tax, penalty, or interest is due the State where such return information has not been filed with the department. A claim of confidentiality shall not prohibit the dissemination of tax information required under this section and shall not constitute grounds for failing or refusing to surrender the tax information to the department in the administration and enforcement of this chapter. Any tax information submitted in compliance with this section shall be treated and afforded with the same confidentiality as a return filed under section 235-116.
HRS § 236E-25