A Senate committee will inquire into possible breaches of environmental conditions at Beeliar Wetlands from Perth Freight Link construction after a Greens motion gained supported from senators.
WA Greens senator Scott Ludlam moved the motion on Thursday and said the project could be proceeding illegally due to breaching it's environmental conditions.
The $1.9 billion Perth Freight Link is the WA Liberal-National government's flagship road project and has become a contentious election issue as Labor will scrap the project and cancel the contracts if elected.
"The heavy handed response to peaceful community protest at Beeliar is in sharp contrast to the repeated obfuscation, indifference and dismissal of the conditions the government itself put in place," Senator Ludlam said.
"At the federal level the government has repeatedly ignored due process and transparency, leaving no recourse but an inquiry into these breaches."
Dozens of protesters have been arrested for opposing land clearing at the Beeliar Wetlands, with some chaining themselves to machinery and fences.
The Environment and Communications References Committee will hold a hearing in Perth late next week.
Labor politician Alannah MacTiernan said the federal government had surrendered planning documents for the Perth Freight Link project on Wednesday, ahead of the third Administrative Appeals Tribunal hearing that was scheduled for Thursday.
Ms MacTiernan made a Freedom of Information application for the documents almost three years ago, and has been battling with the state and federal governments to have the documents released.
She said she would make the documents public before Friday, and they mainly showed public servants scrambling to find data, such as four hours to complete traffic projections.
"Today I was scheduled to be at the AAT for the 3rd time in the almost 3 year battle to get the 'planning' documents that preceded the arrival of the Perth Freight Link in the Federal Budget in May 2014," Ms MacTiernan wrote on Facebook.
"But after spending $150,000+ of taxpayers money hiding information from said taxpayers, the Turnbull Govt surrendered the documents yesterday.
"Mainly they show public servants frantically scrambling to find data to match the project which clearly was framed in the Minister's office eg being 4hrs to do the traffic projections.
"Some entertaining reading but depressing to think we could be spending $2b on such a deeply flawed, unplanned project.
Big thanks to all the solicitors, past and present from Slater and Gordon Lawyers who have helped pro bono on this. More on this later."
- AAP and WAtoday