The presentation, made at a Defense Intelligence Agency conference in May and later posted on the agency's Web site, contained a bar chart showing the growing amount of the U.S. intelligence budget spent on contracts with the private sector since 1994. Although dollar amounts were not shown on the chart, a separate slide said that 70 percent of the budget was currently spent on contract awards.
And, as intelligence blogger R. J. Hillhouse discovered, the edit function of the program used to develop the presentation, Microsoft PowerPoint, reveals a spreadsheet of the actual dollar amounts used to generate the bar chart.
In Fiscal Year 2005 -- the latest period for which full figures are given -- the amount was listed as "#Dollar 4200."
"The numbers are in tens of millions of dollars," writes Hillhouse on her blog, "The Spy Who Billed Me," acknowledging that this is an assumption, but adding it is well known "that the amount spent on contracts is a double-digit billion-plus dollar figure."
"By taking the 70 percent of the intelligence community budget that now goes to contractors in conjunction with the actual dollars spent on contractors, it is possible to reverse-engineer the budget using simple algebra," writes Hillhouse, adding that $42 billion is 70 percent of $60 billion.
A spokeswoman for U.S. Director of National Intelligence Michael McConnell told United Press International that "there are a lot of assumptions being made."
"The presentation was compiled using estimated numbers from a portion of the budget," said Ellen Cioccio. "They are intended to illustrate trends over time. ... They cannot be extrapolated in this fashion."
Cioccio said she could not give any more details because the budget is classified "and we cannot talk about those numbers."
One apparent problem with Hillhouse's reasoning is what it suggests about one recent year for which the intelligence budget was disclosed.
In 1997, after being sued in federal court by government transparency campaigner Steven Aftergood of the Federation of American Scientists, the CIA disclosed that the U.S. intelligence budget for that year was $26.6 billion.
The figure in the spreadsheet for spending on contracts that year is given as 1800 -- which would be $18 billion following Hillhouse's logic.
But this would make contract spending in that year more than two-thirds of the intelligence budget -- almost as much as it is today. Most informed observers believe the proportion spent on contracts has grown significantly since the budget ballooned after the Sept. 11, 2001, terror attacks.
Hillhouse deals with this by suggesting it is "an apples and oranges comparison," because the 1997 figure would have excluded many military intelligence activities. The new numbers, compiled by the Office of the Director of National Intelligence, are much more comprehensive, she argues.
"The numbers the DNI now has ... pick up many (spending) streams that would not have been (included) in that (1997) reported budget," she writes. "The two can't be compared."
Another complicating factor is the now-annual use of supplemental appropriations bills to boost spending in the U.S. war on terrorism. The huge bills -- $93 billion this year -- contain large classified annexes, and much intelligence spending is now funded through these so-called emergency measures.
It is unclear whether the figures in the PowerPoint spreadsheet include supplemental spending -- or indeed what they do include and exclude. The presentation was given by DNI Senior Procurement Executive Terri Everett and was removed last week from the Defense Intelligence Agency Web site.
According to Aftergood, who says the CIA has spent millions fighting his efforts to get intelligence budget data under the Freedom of Information Act, "a certain amount of deliberate obfuscation surrounds the subject such that it is hard to draw a firm numerical conclusion regarding overall spending."
Previous estimates have tended to put the secret budget in the $40-45 billion range. In 2005 a senior intelligence official, Mary Margaret Graham, told a conference on intelligence from satellite photography and other imagery in San Antonio that the annual budget was $44 billion.
But the figure given by Graham, who had no authority over or expertise in the budget, was "significantly wrong," an intelligence official told UPI at the time, declining to elaborate or give a more accurate figure.
The question of whether the so-called top-line, meaning total amount, of the intelligence budget really needs to be classified has been kept open for many years, largely thanks to the advocacy of Aftergood and others, including some lawmakers.
Campaigners say that the total amount of spending is useless information except as a matter of interest to the people whose money it is.
"That aggregate number does not tell you anything about anything -- unless you are a taxpayer who wants to know how much your country spends on intelligence," Aftergood said.
The Sept. 11 Commission recommended declassifying the number, and the U.S. Senate has several times included such a provision in legislation it passed, but the language has never made it into law.