2 U.S.C. § 288g - U.S. Code - Unannotated Title 2. The Congress § 288g. Advisory and other functions

(1) the United States Attorney for the District of Columbia with respect to any criminal proceeding for contempt of Congress certified by the President pro tempore of the Senate pursuant to section 194 of this title;

(2) the committee of the Senate with the responsibility to identify any court proceeding or action which is of vital interest to the Senate;

(3) the Comptroller General, the Government Accountability Office, the Office of Legislative Counsel of the Senate, and the Congressional Research Service, except that none of the responsibilities and authority assigned by this chapter to the Counsel shall be construed to affect or infringe upon any functions, powers, or duties of the aforementioned;

(4) any Member, officer, or employee of the Senate not represented under section 288c of this title with regard to obtaining private legal counsel for such Member, officer, or employee;

(5) the President pro tempore of the Senate, the Secretary of  1 Senate, the Sergeant-at-Arms of the Senate, and the Parliamentarian of the Senate, regarding any subpena, order, or request for withdrawal of papers presented to the Senate which raises a question of the privileges of the Senate; and

(6) any committee or subcommittee of the Senate in promulgating and revising their rules and procedures for the use of congressional investigative powers and with respect to questions which may arise in the course of any investigation.