A member of the following classes shall be presumed to have been lawfully admitted for permanent residence: an alien admitted to the United States before July 1, 1948, in possession of a section 4(a) 1924 Act nonquota immigration visa issued in accordance with State Department regulations, including a child of a United States citizen after he reached the age of 21, in the absence of fraud or misrepresentation; a member of a naturalized person's family who was admitted to the United States as a United States citizen or as a section 4(a) 1924 Act nonquota immigrant on the basis of that naturalization, unless he knowingly participated in the unlawful naturalization of the parent or spouse rendered void by cancellation, or knew at any time prior to his admission to the United States of the cancellation; and a member of a naturalized person's family who knew at any time prior to his admission to the United States of the cancellation of the naturalization of his parent or spouse but was admitted to the United States as a United States citizen pursuant to a State Department or Service determination based upon a then prevailing administrative view, provided the State Department or Service knew of the cancellation.