The 2019 OLA report "Child Care Assistance Program: Assessment of Fraud Allegations" is what makes the claim that greater than 50% of reimbursements to child care providers under these specific programs were fraudulent. That estimate is broadly and bipartisanly considered to be directionally true.
Have you read the document? I often find these things that we believe to be true wind up being a game of telephone. We further have no prior (is the metric of this sort of like how everyone has committed a crime given sufficient prosecutorial attention)?
I've also never heard of this report before this year as someone quite attuned to what happens in Minnesota.
One document contributor contends, notably, that if "adult “employees” spend hours in hallways chatting with other adults [...] the entire amount paid to that provider in a given year is the fraud amount."
I'll leave the assessment of that definition to readers. https://www.auditor.leg.state.mn.us/sreview/ccap.pdf