BailSafe Australia operated an independent GPS monitoring service for accused offenders in Victoria and NSW but shut down more than a week ago.
Neither Victoria Police or the Department of Justice were informed of the Melbourne-based company's closure.
The shutdown did not impact Victoria Police's compliance checks but Premier Jacinta Allan confirmed eight offenders were supposed to be monitored by the company.
"Victoria Police are going through individual assessments and also going through the process to go back before the courts to have bail revoked for these matters," she told parliament in Question Time on Thursday.
She said BailSafe's behaviour was "unacceptable" and the Office of Public Prosecutions and Victoria Police were examining the situation.
Victoria Police confirmed it was only informed of the closure on Wednesday and it was individually assessing the most appropriate course of action, including any immediate compliance checks that are required.
NSW authorities were also caught on the hop, with the company's sudden closure sparking an urgent review by the Department of Communities and Justice.
More than 20 defendants on bail were found to be wearing BailSafe ankle monitors and were referred to police for further action, NSW Attorney-General Michael Daley said.
Victorian shadow attorney-general Michael O'Brien said the Allan government had dropped the ball and failed to properly regulate the sector, calling it the "Wild West".
"No one's done their due diligence," he said.
A trial of ankle monitoring for up to 50 repeat youth offenders on bail is expected to be rolled out in Victoria in coming months.
"You'd be better off putting an AirTag on some of these people," Mr O'Brien said.
"At least you might have a chance of tracking of where they are, because Labor has had an absolute bail fail."
BailSafe Australia could not be reached for comment, with its website, listed email address and phone line no longer functional.
It comes as the Victorian government faces mounting criticism over a review of bail laws after the premier signalled the current arrangements may be too soft.
The Yoorrook Justice Commission, the state's truth-telling inquiry, joined the First People's Assembly and Victorian Aboriginal Legal Service in slamming the move.
Victoria tightened bail laws in 2018 after James Gargasoulas drove into Melbourne's busy Bourke Street Mall in 2017 while on bail, killing six people and injuring dozens more.
The changes were found to be a "complete and unmitigated disaster" in a coronial inquest into Aboriginal woman Veronica Nelson's 2020 death in her cell after she was refused bail on a charge of breaching bail and suspicion of shoplifting.
In a separate inquiry into Victoria's criminal justice system, Yoorrook consistently heard bail laws were "punitive, harsh and harmful" to Aboriginal people.
The government must use the commission's 2023 justice report in its review, Yoorrook chair Eleanor Bourke said.
"It must implement Yoorrook's 46 evidence-based recommendations in full, including in relation to bail," she said.
Police Minister Anthony Carbines suggested the review was not formal, contradicting the premier, who confirmed she expected to announce the outcome within three months.
