The true cost of staging the 2012 Olympics is five times the figure given when London won the bid in 2005.
A Sky investigation has revealed the final cost for the Games will be more than £12bn.
However, associated costs could make the bill as high as £24bn - a staggering 10 times the original estimate.
When London bid for the Games seven years ago the predicted cost of staging the Olympics and Paralympics was put at £2.37bn.
The original public sector funding package, which is primarily cash to build the venues and provide security and policing, was increased in 2007 to about £9.3bn following a review.
However Sky has counted an extra £2.4bn on top of the current £9.3bn public sector funding package for the Games.
The additional cash includes spends on more anti-doping control officers, money for local councils for their Olympic torch relay programmes, cash spent on legacy schemes, paying tube workers not to strike, governmental operational costs, the cost of the Olympic Park Legacy Company, legal bills over the stadium tenancy decision and extra pounds to UK Sport.
The figures also take into account the cost of buying the land for the venues at £766m.
Negotiations are still ongoing about the debt this has left and who will pay for this after the land value becomes considerably lower because of the recession.
The £12bn cost of the Olympics, calculated by Sky, does not include extra counter-terrorism funding of £1.131bn being allocated to the police despite a ministerial statement saying "much of this capacity will be devoted to the Olympics in 2012".
Nor does it include the £4.4bn budgets of the security and intelligence services.
It also does not take into account the opportunity cost of having the majority of the UK police force working on the Games instead of fighting crime elsewhere.
On peak days 12,000 officers will be policing the Games.
In addition, Sky's overall total misses out the £6.5bn spent on transport upgrades which have been brought forward due to the Olympics and could have been cancelled as part of Government spending cuts were it not for the event.
If these figures had been counted, the Olympic spend would have totalled well over £24bn - more than double the current budget and 10 times the original calculation.
The figures also do not consider the cost of actually staging the Games.
This is paid for by the London Organising Committee (Locog), a private company which raises revenues primarily through sponsorship, merchandising and ticket sales.
Locog's budget for the Olympics is £2.1bn.
Sky's Olympic team has counted as many extra Olympic spends as possible across public bodies but there is certainly more spending that has not been accounted for.
Many public bodies have repeatedly ignored Sky's requests for information.
Newham Council, the local authority staging the majority of the Games, provided some figures but requests for further details have been ignored despite contacting them six times.
A number of Freedom of Information requests to the council by members of the public have also failed to get the figures.
But Sky can reveal that they are providing £40m of public money towards the Olympic Stadium conversion and have also spent £700,000 on Olympic projects.
The council spent nearly £1m on their legal costs over the West Ham and Spurs FC row over the stadium and have spent £29,400 on tickets.
As with previous Games, nobody has ever been able to accurately predict the final cost and it will not be until 2013 when we can say whether any increased tourism, economic benefits and the returns from the tenancy or sale of the Olympic venues and village made them a worthwhile investment.
Emma Boon, campaign director for the Taxpayers' Alliance, said: "In some cases it is very difficult to pick apart Olympic spending and separate it out.
"For example, if you look at things like police budgets particularly, it's very difficult to say (whether) those officers would have been on duty that day anyway and whether they are specifically doing Olympic duties or not... To a degree we will never know.
"But I think as far as possible the accounts relating to the Olympics have got to be open, they have got to be honest - publish them on the internet, let taxpayers go and have a look at where their money has gone."
However, Olympics minister Hugh Robertson told Sky News the public spending package is "absolutely" still £9.3bn.
"That in itself is a difficult figure as there is lottery money in that, and there will be money that is repaid when thigns like the broadcast media centre are sold," he said.
Mr Robertson added: "That £9.3bn figure is not a true figure of the cost to the taxpayer."
London Mayor Boris Johnson told Sky News he agreed it was important to assess value for money but insisted the projects would deliver 40,000 jobs, valuable skills and economic growth.
Regarding the decreasing value of some of the land, he said money would return to the public purse when it is built on, he said.
"You can classify a lot of different budget lines and expenditure in the last five, six years and going forward into the future as Olympic-related where they might be delivering regeneration in London, driving economic growth," he said from Davos.
"The transport spend, the land-purchase spend, these are things I think economists might classify it in a different way."
However a Department for Culture, Media and Sport spokesman said: "The Public Sector Funding Package for the Games is £9.3bn and includes all additional security, defence and public transport provision for the Games.
"It is simply not right to start adding on top of that budgets that would have been in existence regardless of 2012 and claim that as being an Olympic cost.
"We have always been transparent about the cost of the Games and have rigorously managed the budget to ensure the programme remains within the £9.3bn.
"London 2012 is an investment in our country that is already bringing in economic benefits that would otherwise not have been possible.
"It is an incredible opportunity for the United Kingdom - not a burden."
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