All taxes imposed by this chapter shall be collectible, together with any interest and penalties thereon, by suit, as other debts of like amount are recoverable. Except in the case of fraud, or omission of a substantial portion of income subject to this tax, or of failure to file a return, an additional assessment shall not be made after 3 years from the time the return was due or filed, whichever is later, provided, however, in those cases in which a commissioner of Internal Revenue and the taxpayer have executed a waiver of the federal statute of limitations, the period within which an additional assessment may be made by the Administrator shall be 1 year from the time of final determination of the federal tax liability.
(1969 Code 92.30)