43 U.S. Code § 902 - Cancellation; investigation before suit
If at any time prior to the institution of suit by the Attorney General to cancel any patent or certification of lands erroneously patented or certified a claim or statement is presented to the Secretary of the Interior by or on behalf of any person or persons, corporation or corporations, claiming that such person or persons, corporation or corporations, is a bona fide purchaser or are bona fide purchasers of any patented or certified land by deed or contract or otherwise, from or through the original patentee or corporation to which patent or certification was issued, no suit or action shall be brought to cancel or annul the patent or certification for said land until such claim is investigated in said Department of the Interior; and if it shall appear that such person or corporation is a bona fide purchaser as aforesaid, or that such persons or corporations are such bona fide purchasers, then no such suit shall be instituted and the title of such claimant or claimants shall stand confirmed; but the Secretary of the Interior shall request that suit be brought in such case against the patentee, or the corporation, company, person, or association of persons for whose benefit the patent was issued or certification was made for the value of the land as hereinbefore specified.
Source(Mar. 2, 1896, ch. 39, § 3,29 Stat. 43.)