Dreamworld's owner Ardent Leisure sought to block the release of 143 pages of critical information relating to ride safety and inspections earlier this year, including a report the Thunder River Rapids ride was "not fit for service".
In July, the Queensland Information Commissioner ordered Dreamworld to release critical documents that detailed years of incident reports, notes from inspections and complaints to the Australian Workers' Union (AWU).
It came after the AWU - which represents workers at the park - requested internal information about safety in order to carry out regulatory activities but was refused.
"Dreamworld broadly objected to disclosure of any documents in relation to the application," the information commissioner's July judgment reads.
The union was eventually forced to narrow its request to specifically include information on rides and plant machinery.
The documents eventually released include details of more than 12 complaints, injury reports and maintenance concerns from 2010 to 2016, The Australian reports.
One note from an October 2012 inspection found that air compressor units on rides - including the Thunder River Rapids - were deemed "not fit for service" while some needed repairs and replacement parts.
Inspector Shaun Langdon said he told Dreamworld "they were taking a risk and if I was a paying customer I wouldn't go on any rides, the condition they were in."
It's unclear what caused the deadly accident on Tuesday. A forensic team is investigating and Dreamworld said all security certifications were up to date. The ride in question was serviced on 29 September and found to be structurally and mechanically sound.
However documents released to the AWU reportedly include complaints about rides being covered in rust, cracks and chips with tape used in some areas. One claims a passenger "ripped open" his knee on a rollercoaster while another claimed to have got his foot and neck stuck between a partition.
The victims
In July, the Information Commissioner took a shot at the company for refusing to supply information saying it was not in its "commercial interests" to prove obstructionist.
"I consider that theme park operators such as Dreamworld are obligated to co-operate with WHSQ inspectors in order to comply with requirements of the WHS Act and to maintain necessary permits and approvals for their continued operation of amusement rides," the document said.
"Given that Dreamworld operates a theme park with various amusement rides as its main attractions, it is unlikely to be in Dreamworld's commercial interests to be uncooperative or obstructionist in its dealings with the regulator."
Dreamworld argued it did not want the AWU using the information as political leverage in negotiations.
The Australian Workers' Union said it raised safety concerns about the park around 18 months ago and claimed a "substantial" number of staff were worried about operation and maintenance of rides.
The AWU Queensland Secretary Ben Swan told SBS: "They have not been cooperative as far as we are concerned with respect to the issues the union has been raising on behalf of its membership."
On Wednesday Dreamworld said it was "fully compliant" in terms of safety certifications at the time of the tragic accident that killed four.
"Park safety is our top priority," a spokeswoman said. "Dreamworld would like to assure the public and our guests that at the time of the incident the park was fully compliant with all required safety certifications."
"As per regulations, this safety audit was conducted by a specialist external engineering firm. Details of this external audit will be provided to the Coroner and workplace safety investigators."
Forensic teams are working establishing the cause of the accident. The park will reopen for a memorial service on Friday.