All prosecutions under this chapter must be commenced within five years from the time of the offense complained of except in the case of failure to file a return, or in the case of filing a false or fraudulent return, in which event the limitation of time within which prosecution must be commenced shall be ten years from the date the return was due or the date the false or fraudulent return was filed. (Ord. 1968-32. Passed 12-27-68.)