London 2012 deputy chairman Keith Mills has told critics that staging the Olympic Games on a shoestring would diminish any regeneration legacy.
Mills was the chief executive of London's 2012 Olympics bid
Olympic Park costs have risen to £3.3bn with some reports claiming the bill for staging the Games could end up at £9bn.
"I think the media has got it wrong. They are lumping together regeneration costs with the cost of running the Games which is ludicrous," he said.
"The running costs and stadium costs for the Olympics have not changed."
He added: "The bottom line is you can run an Olympic Games on a shoestring, put up a temporary venue, but if you haven't actually decontaminated the land you're going to have a building site afterwards.
"The decision for the government is that if you're building a fantastic 500-acre new site, we can invest money and get a return in five or six decades, or we can leave it as a wasteland which, frankly, most of it is now.
"They are spending public money on public infrastructure, in the same way the government are making decisions on new hospitals, new prisons, new schools every day of the week.
"I see this as an investment and it's up to the government to decide how much of an investment they want to make."