Sky Sports News has learned that redevelopment work costing as much as £200m is needed before West Ham move into the Newham venue on a 99-year lease in 2016.
And the Premier League club must hand over just £15m of that figure, with the remainder of the cost borne by the London Legacy Development Corporation (£120m), Newham Council (£40m) and the Government.
Contacted for a response by Sky Sports News, the LLDC said "the stadium transformation has been delivered through public competitive processes to ensure best value for taxpayers".
And a spokesman for West Ham pointed out taxpayers will recoup money for the duration of the 99-year lease in rent, catering receipts and naming rights.
The venue will also host events unrelated to West Ham, including Rugby World Cup games, rock concerts and athletics meetings.
But Leyton Orient chairman Barry Hearn, who has fought a long battle for the right to share the ground, has called West Ham's move "the deal of the century".
And Robert Oxley, campaign director for the Taxpayers' Alliance, told Sky Sports News: "It's incredibly worrying.
"We've already spent £0.5bn in taxpayers' money building the stadium. The idea that we've got to pay nearly another £200m readying the stadium is a terrible deal for taxpayers."