Mr Hayhoe is expected to reveal the full scale of Covid-19 financial fraud when his final report is shared with MPs on Tuesday.
A lack of anti-fraud controls in Covid schemes that were set up quickly by ministers in Boris Johnson's government are expected to be highlighted in the report and blamed for the huge figure.
Rushed rollouts meant "accepting a high level of fraud risk, without plans for managing or mitigating this risk," it will say.
Details of the report were first published by the Sunday Mirror.
In September the government launched a voluntary repayment scheme for people and businesses to return pandemic scheme money with no questions asked until the end of December.
