20.51—Suspension or revocation of permits.
         The appropriate TTB officer may institute proceedings under  part 71 of this chapter to suspend or revoke a permit whenever the appropriate TTB officer has reason to believe that the permittee:
    
    
        
        (a) 
         Has not in good faith complied with the provisions of 26 U.S.C. Chapter 51, or regulations issued under that chapter;
    
    
    
    
    
        
        (e) 
         Has violated or conspired to violate any law of the United States relating to intoxicating liquor or has been convicted of an offense under Title 26, U.S.C., punishable as a felony or of any conspiracy to commit such offense;
    
    
        
        (f) 
         Is, by reason of its operations, no longer warranted in procuring and  dealing in or using specially denatured spirits authorized by the permit; or
    
    
        
        (g) 
         Has not engaged in any of the operations authorized by the permit for a period of more than 2 years.