[This] Memorandum of Understanding (MOU) between the U.S. Treasury Department / Internal Revenue Service (IRS), and the U.S. Department of Homeland Security / U.S. Immigration and Customs Enforcement (ICE), sets forth the agreement of the parties with respect to ICE’s use of the authority in IRC § 6103(i)(2) for the submission of requests for [...] criminal investigation under 8 U.S.C. § 1253(a)(1) or another specifically designated Federal criminal statute.
https://files.epi.org/uploads/IRS_ICE_MOU-April-2025.pdf