Two senators have launched a bipartisan investigation into "taxpayer-funded spin" by the Obama administration, following reports that the administration was devoting millions to promote the health care overhaul and other policies. 

Sens. Rob Portman, R-Ohio, and Claire McCaskill, D-Mo., on Wednesday blasted out letters to 11 federal agencies asking for detailed information about public relations and advertising contracts over the past three years. 

Portman said the probe is "not a partisan exercise." Rather, he said the senators want to bring "to the light of day" how much money the administration is spending to promote its own policies. 

"It's a longstanding concern. ... The question is, what are they paying for public relations services?" Portman told Fox News on Thursday. "Sometimes it's legitimate, to help educate the public about something that the government is doing. ... but often it's spin. And that's the question -- is how much of it is spin, how much of it is inappropriate?" 

Portman, a former Office of Management and Budget director for George W. Bush, said that  administration ran into similar concerns after spending on promotional efforts for the No Child Left Behind law and other policies. But Portman said it's important for lawmakers to be able to "decipher" what promotional campaigns are still being funded -- he cited the ubiquitous side-of-the-road signs promoting the 2009 stimulus law as one example of waste.  

More On This...

Among the many recipients of the senators' letters was the Department of Health and Human Services. A Portman aide, who said the "major document request" was aimed at probing publicly funded "spin," cited a report last summer by watchdog group Judicial Watch that flagged millions of dollars spent on promotion of the federal health care overhaul. 

That report detailed documents that showed federal health officials discussing their campaign with the public relations firm The Ogilvy Group. The officials discussed ways to draw Americans to the website to inform them about provisions in the law. The conversations reflected in part a strategy of targeting women and minorities. One 2010 email from an Ogilvy executive noted that officials wanted to use the "bulk" of paid media efforts "on media that reaches African Americans and Hispanics." 

At the time of the report, HHS confirmed that $3.5 million was spent promoting the site, but argued that the campaign was not out of the ordinary. According to HHS, it was a "critical" way to make sure people are aware of their "rights, protections and benefits" under the health care law. 

The Portman and McCaskill investigation, though, goes far beyond the health department. The senators also sent requests to the Department of Energy, Department of Justice, Environmental Protection Agency, Department of Defense, National Labor Relations Board and other agencies. 

The senators are asking for the names of contractors, the amount of money spent, descriptions of the work and other details. The senators are the top lawmakers on the contracting oversight subcommittee within the Senate Committee on Homeland Security and Governmental Affairs 

The Portman aide, in explaining the broad request, also pointed to a 2010 report by the House Oversight and Government Reform Committee that claimed that "ordinary Americans have financed and been exposed to an unprecedented number of public relations and propaganda efforts" since the start of the Obama administration. 

"The Obama administration frequently used federal resources to promote the president's agenda," the report said. "The president's right to sell his policy recommendations to Congress and the public is not disputed; however, using the resources of the federal government to activate a sophisticated propaganda and lobbying campaign is an abuse of office and a betrayal of the president's pledge to create 'an unprecedented level of openness in government'."