(1) All money in the fund in excess of such an amount as is considered necessary from time to time to meet current payments to retired police officers shall be invested as hereinafter provided. All interest on money belonging to the fund from any source belongs to and must be paid into the fund.
(2) Whenever the money in the police retirement fund exceeds the greater of the following amounts, the city treasurer shall remit the excess to the state treasurer, who shall invest the remittances under the direction of the board of investments as provided in 17-6-204:
(a) 1 1/2 times the monthly benefit paid in the preceding month; or
(b) $5,000.
(3) The funds deposited in the police retirement fund of a city or town after July 1, 1977, are limited to the investments in 17-6-211. However, these funds may be invested under the provisions of 17-6-204.