I'll be happy to provide the link to the U.S. Internal Revenue Code for the release of tax returns;
26 U.S. Code SS 6103 - Confidentiality and disclosure of returns and return information | U.S. Code | US Law | LII / Legal Information Institute
LII U.S. Code Title 26. INTERNAL REVENUE CODE Subtitle F. Procedure and Administration Chapter 61. INFORMATION AND RETURNS Subchapter B. Miscellaneous Provisions Section 6103. Confidentiality and disclosure of returns and return information
Returns and return information with respect to taxes imposed by chapters 1, 2, 6, 11, 12, 21, 23, 24, 31, 32, 44, 51, and 52 and subchapter D of chapter 36 shall be open to inspection by, or disclosure to, any State agency, body, or commission, or its legal representative, which is charged under the laws of such State with responsibility for the administration of State tax laws for the purpose of, and only to the extent necessary in, the administration of such laws, including any procedures with respect to locating any person who may be entitled to a refund. Such inspection shall be permitted, or such disclosure made, only upon written request by the head of such agency, body, or commission, and only to the representatives of such agency, body, or commission designated in such written request as the individuals who are to inspect or to receive the returns or return information on behalf of such agency, body, or commission. Such representatives shall not include any individual who is the chief executive officer of such State or who is neither an employee or legal representative of such agency, body, or commission nor a person described in subsection

. However, such return information shall not be disclosed to the extent that the Secretary determines that such disclosure would identify a confidential informant or seriously impair any civil or criminal tax investigation.