MPs want the government to publish the names of estate agencies and other companies claiming furlough funding.
The all-party Public Accounts Committee of MPs says so-called opportunistic fraud - where furloughed staff continue to work despite companies claiming funds - could be between seven and 34 per cent of cases.
So far during the pandemic some nine million workers have been paid by the government at a cost of £46 billion; an income support scheme for the self employed has cost another £9 billion so far; and government estimates suggest a further £21 billion of taxpayers' money will be paid into the furlough scheme by the end of April next year.
The MPs on the committee - charged with overseeing government expenditure - wants HM Revenue and Customs to name furlough-claiming employers by the end of next month.
"HM Treasury and HMRC should investigate whether more data within and outside of the tax system could be used to determine eligibility for currently excluded groups and write to the committee within six weeks to explain their findings” says the committee.
"Many workers including freelancers and entrepreneurs have not had a penny and are really struggling as they continue to fall through the gaps."
A government spokesperson says: "The furlough scheme has saved millions of jobs and kept businesses in operation. We will consider carefully the findings and recommendations of the Public Accounts Committee report and respond in due course."