David Sullivan has revealed he and fellow West Ham co-chairman David Gold funded the summer signing of Andy Carroll out of their own pockets as the club continues to tackle significant debts.
The England striker completed a loan move to Upton Park from Liverpool towards the end of the summer transfer window with a view to a permanent deal next summer.
He made an instant impact on his debut against Fulham earlier this month, setting up two of West Ham's three goals before limping off with a hamstring injury in the second half.
It was a significant investment by the London club, who were playing Championship football last season and are still paying off debts accrued under their previous ownership.
Sullivan revealed that because of those debts he and Gold are funding the deal for the 23-year-old out of their own pockets.
He also admits that boss Sam Allardyce would have been unable to strengthen the squad at all this summer without their backing.
"We are financing everything out of our own money,' he told the Daily Mail.
"Had we not put money in this year we could not have bought a player. Because there is not sufficient money to pay the debt. I cannot give confidential details of contracts but for the period of time Andy will be with us it's as expensive a player as we have ever signed.
"But our manager thought he was the most important player we could sign this summer and that is why we pursued him. Unfortunately he got this hamstring injury. But that's just bad luck."
Sullivan and Gold took control of the club from Icelandic firm CB Holdings in January 2010 and he concedes the club's finances would have put off most potential owners.
However, he is determined to ensure the club becomes a Premier League force in the short-term, with the long-term aim of becoming financially stable once more.
"As a business venture it made no sense at all," he added. "Not the deal we did.
"The club was £120m in debt with very few assets. It was a mess. I knew, when the Icelandics were signing the players they were for the money they were paying, it made no financial sense
"But David and I are not in it for the money. We don't want to go bust either. The aim is to make the club self-sufficient. But we want to put the best possible team on the pitch for the supporters of West Ham because we are supporters too.
"Because of the mess we inherited we have to service a £100m debt. There are commitments that have to be paid and we have to pay interest on the debt. But we also had to put the money in to put together a team that would get us promoted.
"So we are spending capital. Spending our life savings. There is no point kidding ourselves.
"Now, if the king of Saudi Arabia wants to buy West Ham we would happily step aside for the good of the club. But we wouldn't step aside for a mystery foreign buyer whose financial resources we have no knowledge of."
Sullivan feels one way out of West Ham's financial predicament could be a move to the Olympic Stadium in Stratford.
The Hammers were originally awarded the right to take over the ownership of the stadium last year, but the deal collapsed following legal challenges by Tottenham and Leyton Orient.
They are now one of four formal bidders to become tenants of stadium in a revised bidding process, with Sullivan convinced West Ham have the best bid both for the club and the Olympic legacy.
"Now we obviously want to move to the Olympic Stadium," he added.
"For three years we've been trying to secure it. We believe we have the best bid. We will make football affordable to all because we will have the seats to do deals, and we will make the whole stadium economically viable.
"We will embrace the athletics legacy and make it a brilliant, multi-purpose facility."