Section 6103 of Title 26 of the United States Code governs not only access to tangible tax material (e.g., returns, IRS investigative reports), but also communications regarding such material. See this Manual at 503. Communication between IRS personnel and the prosecutor (e.g., the furnishing by IRS of investigative leads, discussion of IRS investigative results) is severely restricted. Satisfactory communication is possible, however, where disclosure has been obtained pursuant to 26 U.S.C. § 6103(i)(1) or (i)(2).
Under either 26 U.S.C. § 6103(i)(1) or (i)(2), communication between a prosecutor and IRS agent is permissible to the same extent that disclosure is authorized in the court order or request. The prosecutor and the IRS agent can discuss fully the material initially disclosed to the prosecutor. Assuming the order or request authorizes IRS disclosure of subsequently obtained material, discussion and exchange of information can continue within the boundaries of the order or request as dictated by the necessities of the investigation. Separate court orders or requests are required, however, to facilitate communication where the investigation expands to focus on taxpayers not included in the original order or request.
Absent a 26 U.S.C. § 6103(i)(1) court order or a 26 U.S.C. § 6103(i)(2) request, IRS can only provide tax material under 26 U.S.C. § 6103(i)(3) and 26 U.S.C. § 6103(k)(6), both of which inhibit ongoing communication.
Under 26 U.S.C. § 6103(i)(3)(A), 26 U.S.C. § 6103 material may be disclosed by IRS "to the extent necessary to apprise" the prosecutor of the possible commission of a federal crime. See this Manual at 508. The provision appears geared to precipitating a 26 U.S.C. § 6103(i)(1) or (i)(2) request and not to supplying a flow of investigative leads. Assuming the latter use is not improper, the material, once disclosed by IRS, could be discussed with an IRS agent where an investigation could not otherwise be properly conducted. Unlike 26 U.S.C. § 6103(i)(1) and (i)(2), 26 U.S.C. § 6103(i)(3)(A) requires that all disclosures -- initial and subsequent -- be in writing. Communication subject to such an impediment appears overly cumbersome.
By contrast, 26 U.S.C. § 6103(i)(3)(B) does not require that disclosures be in writing, which is sensible since it pertains to emergency circumstances. The provision appears to be geared to supplying investigative leads calling for an immediate response by law enforcement authorities, and thus communications between IRS and law enforcement authorities should be uninhibited under 26 U.S.C. § 6103(i)(3)(B).
Under 26 U.S.C. § 6103(k)(6), 26 U.S.C. § 6103 material may be disclosed to a prosecutor by an IRS agent "to the extent that such disclosure is necessary in obtaining information, which is not otherwise reasonably available," for purposes of tax administration. The provision is designed to allow an IRS investigator to make limited disclosures for purposes of completing a tax case, but does not contemplate aiding the prosecutor with the preparation of a non-tax criminal case. Thus, a prosecutor may not receive all the material relevant to the non-tax criminal case and, under 26 U.S.C. § 6103(k)(6), has no way of ascertaining the extent of relevant material withheld. No genuine exchange of information is possible under 26 U.S.C. § 6103(k)(6).