Victoria's Commission for Children and Young People has revealed in its 2020/21 annual report that 45 kids known to state protection services died over the last financial year.

In two of those deaths, it was identified services decreased face-to-face contact with the child and their family because of coronavirus restrictions.

The commission said, in both cases, services individually chose not to have direct contact without first consulting with other services involved with the child and their family.

"The commission found that reduced face-to-face contact meant that child protection was unable to adequately assess risks faced by children experiencing significant vulnerability," said the report, among more than 200 tabled in state parliament on Thursday.

"It also meant that the direct supports previously provided by multiple services ceased at a critical time."

Of the 45 total deaths, 13 were Aboriginal children and 30 were under the age of four.

The most common causes of death were by accident (nine), illness (nine) and sudden unexpected death in infancy (eight). Four children's deaths were attributed to suicide.

Vulnerable child deaths in Victoria have spiked to the highest recorded level since 2011 over the past two years, after a further 51 were reported in 2019/20.

The commission said the rise was attributable to a 39 per cent increase in illness-related deaths.

Of its 41 inquiries relating to children who died from 2018 to 2021, an average of three reports were made to child protection services before their deaths. There was 29 reports in one case.

The commission found there had been "inadequate risk assessment for children and young people" in 17 of its inquiries, leaving children at "ongoing risk of significant harm, sometimes over a significant period".

It has previously called on the Victorian government to develop and implement an integrated, whole-of-system investment model and strategy for the state's child protection system.

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Australian Associated Press