Me. Rev. Stat. tit. 5, § 125

The Treasurer of State may not in any way receive for the Treasurer of State's own use any interest, premium, gratuity or benefit by reason of any money belonging to the State, or of any loan obtained for the State or for keeping on hand or circulating the bills of any bank; but whatever is so received must be accounted for to the State. The Treasurer of State may not loan or use in the Treasurer of State's own business, or for the Treasurer of State's own benefit, any such money, or permit any other person to do so, unless authorized by law, on pain of forfeiting a sum equal to the amount so used or loaned, to be recovered by indictment.