§ 801. Conflicts of interest prohibited. Except as provided in section eight hundred two of this chapter, (1) no municipal officer or employee shall have an interest in any contract with the municipality of which he is an officer or employee, when such officer or employee, individually or as a member of a board, has the power or duty to (a) negotiate, prepare, authorize or approve the contract or authorize or approve payment thereunder (b) audit bills or claims under the contract, or (c) appoint an officer or employee who has any of the powers or duties set forth above and (2) no chief fiscal officer, treasurer, or his deputy or employee, shall have an interest in a bank or trust company designated as a depository, paying agent, registration agent or for investment of funds of the municipality of which he is an officer or employee. The provisions of this section shall in no event be construed to preclude the payment of lawful compensation and necessary expenses of any municipal officer or employee in one or more positions of public employment, the holding of which is not prohibited by law.