Serco has declared its guards were not to blame for the escape of three prisoners this month.
The British firm says it will not discipline the staff who were on duty when a notorious rapist and two other prisoners escaped.
Rapist Cameron John Graham and alleged armed robber Kelden Edward Fraser kicked their way out of a prison van at Geraldton airport on January 3. The maximum-security prisoners were recaptured after 36 hours.
Two weeks later, Bradley McIntosh-Narrier smashed his way out of a public toilet in Joondalup Health Campus' emergency department.
The alleged burglar was recaptured 47 hours later after allegedly going on a crime spree in the eastern suburbs.
Serco, which holds the $50 million-a-year contract to run WA's court security and custodial services, has previously refused to reveal if action was being taken against the guards on duty when the escapes happened, saying investigations were continuing.
But the company has now said it has cleared its staff of fault.
"Following each of these two escapes, our initial assessments indicated that our staff had followed procedure," a spokesman said. "Staff have not been stood down in either case and are not subject to disciplinary process.
"In each case we took immediate action with the Department of Corrective Services to improve security measures."
Corrective Services Commissioner James McMahon said last night that changes to procedure were made immediately after both escapes and he was waiting for the findings of investigations into both incidents.
"Only when the detailed investigations are completed, and due diligence and procedures are applied, will it be appropriate to consider any disciplinary action or abatements consistent with the contract with Serco," he said.
Corrective Services Minister Joe Francis' spokeswoman said the Government was waiting for the investigation and report to be completed before making further comment.
Serco's contract imposes a fine of $100,000 for each prisoner escape from a secure environment and $30,000 for an escape from an unsecure environment.
Serco's spokesman said the company regretted the escapes had occurred.
Mr McMahon has said the reasons for the Geraldton escape were procedural and mechanical.
It is understood the internal door to the prison van pod may not have been properly locked.
The Transport Workers Union said the guards had opened the van's external door to give the prisoners ventilation.