Minn. Stat. § 151.30

It shall be the duty of the county attorney of the county wherein any offense under this chapter is committed to prosecute the offender, except that when offenses hereunder are committed in cities of the first class it shall be the duty of the city attorney thereof to prosecute the offender. Such prosecutor is authorized to examine the books of any manufacturer or wholesale dealer within the state for the purpose of acquiring information to aid in the prosecution.