A local council has arranged a £40m loan to finance West Ham's potential move into the Olympic Stadium.
The club is going head-to-head with Tottenham Hotspur to take over the site after the 2012 Games.
Councillors at the Labour-run Newham Council voted in favour of the loan, calling it a "strong package".
A BBC London investigation had raised a series of concerns about how the decision to loan the money was reached.
West Ham will have access to the loan, secured by the council from the Treasury, if they are named preferred bidder by the Olympic Park Legacy Company at the end of January.
Council chief executive Kim Bromley-Derry said: "We are unable to comment on financial aspects of the Newham Council and West Ham United bid for the Olympic Stadium because of a confidentiality agreement with the Olympic Park Legacy Company.
"However our proposal offers a strong financial package with no further call on the public purse."
It emerged before the vote that councillors had been unable to examine all the financial details until the last minute.
A "significant number" of backbench councillors were known to have reservations but were said to be "afraid" to speak out over fear of losing out on highly-paid advisory roles.
There were also impartiality questions over dozens of gifts from the club to Mayor of Newham Sir Robin Wales.
The council has insisted the mayor had "nothing to hide" over hospitality he received from the club, although it meant Sir Robin was unable to take part in the vote.
It did not comment on the advisory roles.
Speaking after the vote, Mike Law, a former Labour councillor who defected to the Conservatives, said: "I am not surprised it went through - the whole vote was just window dressing.
"If you look at the constitution the mayor is the sole decision maker - so it makes a mockery to say he's not involved because he didn't vote.
"Elected members in Newham had not been briefed properly, and they have been hoodwinked into ratifying a decision that had already been made."
After the vote a council spokesman refused to say whether it would be liable for the debt if West Ham defaulted, citing commercial confidentiality.