An official report claiming that London 2012 was worth £9.9 billion to UK trade is a “marketing exercise”, Vince Cable has admitted.
The Business Secretary said the figures may not survive “a rigorous academic approach” but added they were "the best we can do".
When grilled on the report on the BBC Radio Four Today programme, Cable said it was "essentially a marketing exercise, using methods approved by the National Audit Office, which is a very tough test."
He added: "It is the best we can do – it is not necessarily something that would pass muster in the best academic journals but a test of credibility has been applied to it."
The Government's £9.9 billion figure includes investments such as £1 billion for "regeneration in the centre of Croydon", 16 miles away from the Olympic Park.
A small business leader has questioned whether the Olympic effect was felt outside London, saying many regional businesses put in work for contracts that "didn't materialise".
The national policy chairman of the Federation of Small Businesses, Mike Cherry, told the BBC:
– Mike Cherry
Out in the regions, we found that the effect of the Olympics and Paralympics, and the contracts we were expecting, really didn't materialise as much as I suspect many people were hoping for.
A lot of work went into it at the very beginning, when it was all announced. But although some businesses certainly got some really good contracts, for the vast majority it just didn't happen.
- The overall cost of London 2012 was £8.92 billion, the Government revealed in October.
- That worked out at £142 per head for every UK resident.
- The Games came in under budget, with £9.3 billion set aside.
- The predicted cost when London won the bid in 2005 was just £2.37 billion.
- Today's report says the Games gave the UK economy a £9.9 billion trade and investment boost.
- It added that the total benefit to the UK could reach up to £41 billion by 2020.
Olympic gold medallist Jessica Ennis has told ITV News the London 2012 legacy is that children "want to get involved in sport":
Boris Johnson said the "Olympo-sceptics" were proved wrong by success of the London 2012 Games after it was announced the Olympics gave the UK economy a £9.9 billion boost.
The Mayor of London said the country would now "defy the doom-mongers" when it comes to securing a permanent Olympic legacy.
"London is succeeding where virtually no other host city has, on track to secure a solid gold payback on the taxpayers' outlay and a rosy future for the Queen Elizabeth Olympic Park", Mr Johnson added.
Business Secretary Vince Cable said there was "no doubt" that the London 2012 Games was "a success story" for British business after it was revealed the UK economy received a £9.9 billion boost from the event.
Mr Cable said this has created "a multi-billion pound business springboard to take British expertise to the world", and UK Trade and Investment (UKTI) is "working hard" to make the most of the opportunity.
"Reaching £9.9 billion in the space of one year is an amazing achievement. I hope that companies of all sizes up and down the country follow suit and use the positive impact generated by the Games to reach out to new markets and grow their businesses", he added.
David Cameron said the £9.9 billion boost the UK economy received from the London 2012 Games shows "you should think British".
The Prime Minister said it is "a reminder to the world that, if you want the best, if you want professionalism, if you want jobs done on time and on budget then you should think British".
Mr Cameron also highlighted the "social legacy" of the Olympics and Paralympics, saying "thousands of people have been inspired" following the success of the Games Makers volunteers.
The London Olympic and Paralympic Games gave the UK economy a £9.9 billion trade and investment boost, according to a new report.
The increase came from businesses securing contract wins, additional sales and new foreign investment in the last year, the Government and London Mayor Boris Johnson said.
Strong progress has been made against all the legacy commitments including an increase in volunteering, 1.4 million more people playing sport at least once a week than when the bid was won in 2005 and the legacy of the permanent venues in the Olympic Park secured within a year of the Games.
Independent research projects that the total benefit to the UK from hosting London 2012 could reach up to £41 billion by 2020, the report added.