22 CFR § 42.82 - Revocation of visas.
(a) Grounds for revocation by consular officers. A consular officer, the Secretary, or any Department official to whom the Secretary has delegated this authority is authorized to revoke an immigrant visa at any time, in his or her discretion.
(b) Provisional revocation. A consular officer, the Secretary, or any Department official to whom the Secretary has delegated this authority may provisionally revoke an immigrant visa while considering information related to whether a visa holder is eligible for the visa. Provisional revocation shall have the same force and effect as any other visa revocation under INA 221(i).
(c) Notice of revocation. Unless otherwise instructed by the Department, a consular officer shall, if practicable, notify the alien to whom the visa was issued that the visa was revoked or provisionally revoked. Regardless of delivery of such notice, once the revocation has been entered into the Department's Consular Lookout and Support System (CLASS), the visa is no longer to be considered valid for travel to the United States. The date of the revocation shall be indicated in CLASS and on any notice sent to the alien to whom the visa was issued.
(d) Procedure for physically canceling visas. An immigrant visa that is revoked shall be canceled by writing or stamping the word “REVOKED” plainly across the face of the visa, if the visa is available to the consular officer. The failure or inability to physically cancel the visa does not affect the validity of the revocation.