31 U.S.C. § 3341: Sale of Government warrants, checks, drafts, and obligations

(a) A disbursing official of the United States Government may sell a Government warrant, check, draft, or obligation not the property of the official at a premium, or dispose of the proceeds of the warrant, check, draft, or obligation, only if the official deposits the premium and the proceeds in the Treasury or with a depositary for the credit of the Government. (b) A disbursing official violating subsection (a) of this section shall be dismissed immediately.