The findings from an investigation into a major derailment on WA's ageing grain freight rail lines will remain secret despite intense public interest in the future of the taxpayer-owned network.
Brookfield Rail and CBH, which employs contractor Watco to operate its locomotives and wagons, rejected requests to make the findings public.
A Brookfield spokeswoman said the derailment report - which involved Brookfield, Watco and the Office of Rail Safety - would not be released because it included confidential commercial and personnel information.
The derailment on the 117-year-old York-to-Quairading line was used to justify its closure on safety grounds just before the start of a record-breaking harvest in WA.
Brookfield, which has an exclusive lease over the State's rail freight network, and CBH are locked in a bitter dispute over a long-term access agreement to the lines referred to as Tier 1, 2 and 3.
The period for the public submissions to the Economic Regulation Authority closes today.
Submissions from local governments and the Wheatbelt Railway Retention Alliance hit out at the secrecy surrounding the lease and its administration by the Public Transport Authority.
The WA Local Government Association said Brookfield's access charges should relate to the service provided.
The Shire of Quairading said the closure of the rail line to York would create more than 10,000 additional road-train movements on the Quairading-Cunderdin Road and the York-Merredin Road in the first eight months of this year.
It said the high level of fatalities on Wheatbelt roads was already a major concern. The ERA is set to approve or determine relevant floor and ceiling prices for access by the end of the month.
A parliamentary committee investigating is to deliver its findings in August.