BOSTON — The so-called bid book that Boston business leaders presented last year to the United States Olympic Committee helped the city win the competition over Los Angeles, San Francisco and Washington as America’s candidate to host the 2024 Summer Games.

But now, that document may end up being the city’s undoing.

Boston 2024, the group of private business leaders who crafted the bid last year out of public view, has maintained that the Games would be paid for with private money.

But the bid book, which was obtained this week by local news organizations, said the opposite — that the Games would also need public money.

Boston 2024 said that the bid book was in the “proof of concept” stage and that the group was preparing a new plan, with new financial figures and new venues, to release in late June. “We stand by our commitment that the operations of the Games and the building of venues will be privately funded,” Boston 2024 said in a statement.