More than 200 billion US dollars (£157 billion) may have been stolen from two large Covid-19 relief initiatives, according to new estimates from a federal watchdog investigating federally funded programmes that helped small businesses survive the worst public health crisis in more than a hundred years.

The numbers issued on Tuesday by the US Small Business Administration (SBA) inspector general are much greater than the office’s previous projections and underscore how vulnerable the paycheck protection (PPP) and Covid-19 economic injury disaster loan (Covid-EIDL) programmes were to fraudsters, particularly during the early stages of the coronavirus pandemic.

The inspector general’s report said “at least 17% of all Covid-EIDL and PPP funds were disbursed to potentially fraudulent actors.”

The fraud estimate for the Covid-EIDL is more than 136 billion US dollars (£107 billion), which represents 33 percent of the total money spent on that programme, according to the report.

The PPP fraud estimate is 64 billion dollars (£50 billion), the inspector general said.

In comments attached to the report, a senior SBA official disputed the new numbers.

Bailey DeVries, SBA’s acting associate administrator for capital access, said the inspector general’s “approach contains serious flaws that significantly overestimate fraud and unintentionally mislead the public to believe that the work we did together had no significant impact in protecting against fraud”.

The SBA inspector general had previously estimated fraud in the Covid-EIDL programme at 86 billion dollars (£67 billion) and the PPP at 20 billion US dollars (£16 billion).

The Associated Press reported on June 13 that scammers and swindlers potentially swiped about 280 billion dollars (£220 billion) in Covid-19 emergency aid; another 123 billion dollars (£96 billion) were wasted or misspent.

The bulk of the potential losses are from the two SBA programmes and another to provide unemployment benefits to workers suddenly unemployed by the economic upheaval caused by the pandemic.

The three initiatives were launched during the Trump administration and inherited by President Joe Biden.

Combined, the loss estimated by AP represents 10% of the 4.2 trillion dollars (£3.3 trillion) the US government has so far disbursed in Covid relief aid.

The SBA inspector general, Hannibal “Mike” Ware, said in a statement on Tuesday that the report “utilises investigative casework, prior (inspector general) reporting, and cutting-edge data analysis to identify multiple fraud schemes used to potentially steal over 200 billion US dollars (£157 billion) from American taxpayers and exploit programmes meant to help those in need.”

Mr Ware, in an interview with the Associated Press earlier this month, said that these latest fraud figures will not be the last ones issued by his office.

“We will continue to assess fraud until we’re finished with the investigations on these things,” Mr Ware said.

That could be a long while. Mr Ware’s office has a backlog of more than 90,000 actionable leads into pandemic relief fraud, which amounts to nearly a century’s worth of work.

SBA previously told The Associated Press the federal government has not developed an accepted system for assessing fraud in federal programs.

Previous analyses, the agency said, have pointed to “potential fraud” or “fraud indicators” in a manner that conveys those numbers as a true fraud estimate when they are not.

For the Covid-19 EIDL programme, the agency said it’s “working estimate” found 28 billion dollars (£22 billion) in likely fraud.

Han Nguyen, a spokesman for the SBA, said in a statement on Tuesday that it is “vital to clarify that 86% of the likely fraud in the PPP and Covid-EIDL programs occurred in the first nine months of those programs when, as the (inspector general) has often noted, the rush to get funds out led to unwise decisions to pull down anti-fraud guard rails.”