When any person who is obligated to approve, audit, allow or pay claims or demands upon the state, approves, audits, allows or pays, or consents to, or connives at, approving, auditing, allowing or paying a claim or demand against the state not authorized by law, such person, and the person in whose favor the claim or demand was made, shall be liable for any funds procured in such manner, plus twenty per cent of such amount and legal interest upon the amount paid from date of payment.