Joshua Dale Brown has been charged with more than 70 sex offences after allegedly abusing eight children aged under two at a childcare facility at Point Cook, in Melbourne's southwest.
The 26-year-old worked in at least 20 centres since 2017, for which a list and set of dates have already been made public.
But Victoria Police said they were continuing to investigate further details of his employment history as a matter of priority after parents reported discrepancies in the listed dates.
"We understand that many in the community are feeling concerned and anxious, however it is incredibly important that this information is confirmed, then thoroughly reviewed with other relevant agencies prior to any public release," a police spokeswoman said.
Childcare operator Affinity Education, which operates several facilities where Brown worked, is reviewing its records following reports he might have been employed longer than first thought.
The families of 1200 children have been told to get the infants tested for sexually transmitted infections as a precaution.
Parents have contacted the Australian Childhood Foundation complaining they're not getting adequate communication from authorities or childcare centre management.
"We're dropping the ball," the charity's chief executive Janise Mitchell told AAP.
She supported the police investigation but added there needed to be a constant line of communication to the families most closely impacted.
"What that loses sight of is the anxiety, the terror, the fear parents are laying awake with every night, wondering where they sit in the unfolding scenario," Ms Mitchell said.
"In the absence of communication, fear grows, mistrust grows, and anxiety grows that there's something going on."
Families of the children recommended for STI testing are anxiously awaiting results, with several told to get their infants checked twice.
They were first told to get their child checked for two diseases and then days later were warned about the need to test for a third.
State, territory and federal education ministers are due to meet in August and they will discuss tighter safety measures, including the introduction of CCTV in centres and a national register of childcare workers.
NSW has flagged a trial of CCTV cameras in centres, as an urgent Victorian review examines making the technology mandatory.
South Australia is considering cameras and fast-tracking mobile phone bans in childcare centres while Western Australia is conducting a child safety review into facilities there.
The Albanese government also plans to fast-track legislation to allow funding to be stripped from centres that don't meet standards, while spot checks will be introduced to limit fraud.
But a former royal commissioner has slammed governments for dragging their feet on creating a national regime for working with children checks after an inquiry in 2015 issued the recommendation.
Brown had a valid working with children check and was not known to police or subject to any complaints before his arrest in May.
Robert Fitzgerald, one of five members of the royal commission, said it was shameful the recommendation remained unfulfilled.
"Ten years on, that job should have been completed and the fact that it isn't means there are gaps in our child safeguarding regime," the now-age discrimination commissioner said.
Every state and territory maintains separate working with children schemes with different rules and requirements.
Victoria, Queensland and NSW have all committed to reviewing or tightening up their regimes.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
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