Ambulance Victoria on Thursday confirmed the staff members were suspended after allegations of serious misconduct.
Chief executive Jane Miller was tipped off to the accusations by an employee in early 2023, with the matter referred to the Independent Broad-based Anti-Corruption Commission (IBAC) and Ambulance Victoria launching an internal investigation.
"This process remains under way," an Ambulance Victoria spokesperson said in a statement.
Ambulance Victoria chief Jane Miller says an investigation has been launched into the allegation. (Diego Fedele/AAP PHOTOS)
"As this matter is under investigation, it is not appropriate to provide any further comment."
The suspended members of the payroll department have been accused of claiming overtime for hours they did not work and not logging on for rostered shifts, multiple outlets report.
The Herald Sun reported the workers allegedly embezzled $3.5 million from the government agency.
Victorian Ambulance Union secretary Danny Hill confirmed the accused workers were not paramedics or operational staff.
"Sadly, paramedics responding to emergencies have reported being abused by members of the public this morning with reference to this story," he said.
"They have absolutely no involvement in this matter and deserve to be treated respectfully."
Premier Jacinta Allan said she was made aware of the allegations on Wednesday and slammed the implicated staff.
"I'm deeply concerned about ... the allegations of this disgraceful behaviour," she told reporters on Thursday.
"This alleged behaviour is absolutely unacceptable in the public sector, in the private sector.
"But we do need to let this investigation come to its conclusion to be able to comment further on what further action will no doubt need to be taken to deal with this behaviour."
Opposition health spokeswoman Georgie Crozier has questioned why "no action" has been taken. (Joel Carrett/AAP PHOTOS)
Opposition health spokeswoman Georgie Crozier said the claims should have been referred to Victoria Police.
She questioned why "no action" had been taken despite the accusations of stolen taxpayer funds emerging more than a year ago.
"It just demonstrates the extent of the chaos and dysfunction that is going on in this very important agency," Ms Crozier said.
The premier would not be drawn on whether the government would consider appointing administrators to run the ambulance service but said she still had confidence in its executive team.
Victorian ambulance union members are voting on a motion of no confidence in the AV executive amid stalled pay talks and plan to rally outside the office of Heath Minister Mary-Anne Thomas on Friday.
An IBAC spokeswoman said the watchdog does not comment on whether it has a complaint or investigation before it.