(1) All public utilities, the rates of which are subject to regulation under the provisions of this chapter, shall file with the commission copies of contracts, wherein the consideration therefor is One Million Dollars ($1,000,000.00) or more, with any holding, managing, operating, constructing, engineering or purchasing company, which is an affiliate of or a subsidiary of, such public utility, and when requested by the commission, copies of such contracts wherein the consideration therefor is less than One Million Dollars ($1,000,000.00) and copies of contracts with any person selling service of any kind. The commission may, after hearing on reasonable notice, disallow any payment to be capitalized or included as an operating cost of the public utility in the fixing of rates or as an asset in fixing a rate base under any such contract if it is found by the commission to be unjust or unreasonable, or made for the purpose or with the effect of concealing, unreasonably transferring or unreasonably dissipating the earnings of the public utility. Provided, however, that in the case of a public utility with fewer than twenty-five thousand (25,000) customers, this subsection shall apply only to such contracts as the commission shall request such public utility to file.

(2) No public utility as described in subsection (1) of this section shall pay any fees, commission or compensation of any description whatsoever to any affiliated or subsidiary holding, managing, operating, constructing, engineering or purchasing company for services rendered or to be rendered without first filing copies of all agreements and contracts therefor with the commission. The commission may, after hearing on reasonable notice, disallow any such payment to be capitalized or included as an operating cost of the public utility in the fixing of rates or as an asset in fixing a rate base under such agreement or contract if it is found by the commission to be unjust or unreasonable. Provided, however, that this subsection shall not apply to motor carriers of passengers.

(3) The public service commission staff, upon direction of the commission, shall have full power and authority to investigate any such contract, arrangement, purchase or sale, and no payment disallowed by the commission shall be capitalized or included as an operating cost of the public utility in the fixing of rates or as an asset in fixing a rate base. If, in any such investigation, the public utility or affiliate shall unreasonably refuse to comply with any request of the commission for information with respect to relevant accounts and records, whether of such public utility or any affiliate, any portion of which may be applicable to any transaction under investigation, so that such parts thereof as the commission may deem material may be made part of the record, such refusal shall justify the commission in disapproving the transaction under investigation and disallowing payments in pursuance thereof, to be capitalized or included as an operating cost of the public utility in the fixing of rates or as an asset in fixing a rate base.