Any contracts or agreements approved prior to June 26, 1936, by the Secretary of the Interior between the authorities of any tribe, band, or group of Indians and their attorneys for the prosecution of claims against the United States, which provide that such contracts or agreements shall run for a period of years therein specified, and as long thereafter as may be required to complete the business therein provided for, or words of like import, or which provide that compensation for services rendered shall be on a quantum-meruit basis not to exceed a specified percentage, shall be deemed a sufficient compliance with section 81 of this title: Provided, however, That nothing herein contained shall limit the power of the Secretary of the Interior, after due notice and hearing and for proper cause shown, to cancel any such contract or agreement: Provided further, That the provisions of this section and section 81b of this title shall not be construed to revive any contract which has been terminated by lapse of time, operation of law, or by acts of the parties thereto.

Any existing valid contract made and approved prior to June 26, 1936, pursuant to any Act of Congress by any tribe, band, or group of Indians with an attorney or attorneys for the rendition of services in the prosecution of claims against the United States under authority of which suit or suits have been filed, and which contains a limitation of time for the completion of the services to be performed may be continued in full force unless a subsequent contract dealing with the same subject matter has been made and approved.

No money shall be paid to any agent or attorney by an officer of the United States under any such contract or agreement, other than the fees due him for services rendered thereunder; but the moneys due the tribe, Indian, or Indians, as the case may be, shall be paid by the United States, through its own officers or agents, to the party or parties entitled thereto; and no money or thing shall be paid to any person for services under such contract or agreement, until such person shall have first filed with the Commissioner of Indian Affairs a sworn statement, showing each particular act of service under the contract, giving date and fact in detail, and the Secretary of the Interior and Commissioner of Indian Affairs shall determine therefrom whether, in their judgment, such contract or agreement has been complied with or fulfilled; if so, the same may be paid, and, if not, it shall be paid in proportion to the services rendered under the contract.

Contracts involving the payment or expenditure of any money or affecting any property belonging to the Choctaw, Chickasaw, Cherokee, Creek, or Seminole Tribes of Indians, including contracts for professional legal services, may be made by said tribes, with the approval of the Secretary of the Interior, or his authorized representative, under such rules and regulations as the Secretary of the Interior may prescribe: Provided, That the provisions of this section shall not apply to contracts for professional legal services involving the prosecution of claims against the United States.

No contract made with any Indian, where such contract relates to the tribal funds or property in the hands of the United States, shall be valid, nor shall any payment for services rendered in relation thereto be made unless the consent of the United States has previously been given.

Land allotted to any applicant for enrollment as a citizen in the Five Civilized Tribes whether an Indian or freedman, shall not be affected or encumbered by any deed, debt, or obligation of any character contracted prior to the time at which said land may be alienated under the laws of the United States: Provided further, That the interest accruing from tribal funds and deposited in banks in the State of Oklahoma may be used as authorized by the Act of March third, nineteen hundred and eleven, under the direction of the Secretary of the Interior, to defray the expense of per capita payments authorized by Congress.

Any disbursing or other officer of the United States, or other person, who shall knowingly present, or cause to be presented, any voucher, account, or claim to any officer of the United States, for approval or payment, or for the purpose of securing a credit in any account with the United States, relating to any matter pertaining to the Indian Service, which shall contain any material misrepresentation of fact in regard to the amount due or paid, the name or character of the article furnished or received; or of the service rendered, or to the date of purchase, delivery, or performance of service, or in any other particular, shall not be entitled to payment or credit for any part of said voucher, account, or claim; and if any such credit shall be given or received, or payment made, the United States may recharge the same to the officer or person receiving the credit or payment, and recover the amount from either or from both, in the same manner as other debts due the United States are collected: Provided, That where an account contains more than one voucher the foregoing shall apply only to such vouchers as contain the misrepresentation: And provided further, That the officers and persons by and between whom the business is transacted shall, in all civil actions in settlement of accounts, be presumed to know the facts in relation to the matter set forth in the voucher, account, or claim: And provided further, That the foregoing shall be in addition to the penalties prescribed by law, and in no way affect proceedings under existing law for like offenses. Where practicable this section shall be printed on the blank forms of vouchers provided for general use.