It shall be lawful for trustees, executors, administrators, guardians and other fiduciaries, the State of Alabama and any of its departments, boards, institutions and agencies, and the municipalities, counties and other political subdivisions of the state to invest their funds and the moneys in their custody or possession eligible for investment in notes or bonds secured by mortgage or trust deed insured by the Secretary of Housing and Urban Development or his predecessor officer pursuant to the laws and regulations governing the insurance of such as now constituted or as hereafter amended and in debentures issued by such official.