Homeland Security Department "fusion centers" designed to improve the analysis of terrorism intelligence have largely failed in their mission and in some instances have violated Americans' civil liberties, according to a bipartisan Senate investigation that accused the Obama administration of hiding the problems from Congress.

"Fusion centers forwarded 'intelligence' of uneven quality – oftentimes shoddy, rarely timely, sometimes endangering citizens’ civil liberties and Privacy Act protections, occasionally taken from already-published public sources, and more often than not unrelated to terrorism," said the scathing report, to be released Wednesday by the Senate's Homeland Security and Governmental Affairs Subcommittee on Investigations.

In addition, the Senate report said, the Homeland Security Department has kept under wraps reports showing the centers' failures, and has stated that some fusion centers existed when they didn't.

Between 2003 and 2011, the government poured hundreds of millions of dollars into more than 70 state and local fusion centers, which are supposed to help monitor and analyze counterterrorism data at local levels and assist federal agencies in "connecting the dots" so terrorist attacks on the United States are prevented.

But a two-year investigation found "senior DHS officials were aware of the problems hampering effective counterterrorism work by the fusion centers, but did not always inform Congress of the issues, nor ensure the problems were fixed in a timely manner," the report said.

DHS had already conducted its own evaluation of the centers in 2010 that found "widespread deficiencies," but didn't tell Congress or make the report public, the Senate probe found.  The senators said that when they asked for the report, DHS denied it existed - before finally turning over a copy.

The Homeland Security Department wasn't even able to come up with an accurate amount of how much its paid for the fusion centers, senators said, estimating the cost was between $289 million and $1.4 billion.

DHS spokesman Matthew Chandler told the Associated Press the report was "out of date, inaccurate and misleading." He said it focused entirely on the information being produced by the fusion centers, but did not consider the benefit the involved officials got receiving intelligence from the federal government, the AP reported.

The withering assessment contradicts public statements Homeland Security Department officials highlighting the centers as integral to the nation's counterterrorism capabilities.

"What I will be advocating as the Secretary of Homeland Security is that fusion centers are the centerpiece of state and local information-gathering and sharing for us across the country," DHS Secretary Janet Napolitano said at the National Fusion Center Conference in 2009.

But the investigation found there have been no reports from fusion centers that helped uncover or disrupt a terrorist plot.  Instead, 188 of the 610 reports produced were never published because they lacked useful information or "potentially violated department guidelines meant to protect Americans’ civil liberties or Privacy Act protections," according to the Senate report.

Other fusion center reports were delayed so long that by the time they were finally published they were obsolete, the investigation found.  Still others were about non-terrorism threats such as drug smuggling, or were only taken from media reports about terrorism.

One fusion center chief interviewed by the subcommittee said that although he was sometimes proud of the information his unit produced, "There were times when it was, ‘what a bunch of crap is coming through.'"

A lack of oversight also contributed to the problems, as the senators found DHS required only one week of training before sending officials to fusion centers, and those that repeatedly reported useless or potentially illegal information suffered no reprimands.

Instead of focusing on their duties, some fusion centers decided to play spy, the senators said, purchasing hidden cameras, cell phone trackers and other surveillance equipment that had little to do with the focus on analyzing information.

The fusion centers could be useful in helping traditional criminal investigations, improving public safety, or assisting in disaster response, the report said, but have done little to aid counterterrorism work, especially compared to other similar structures elsewhere in the government, such as the FBI's Terrorist Screening Center.

But the Senate subcommittee reserved some criticism for itself, saying lawmakers too should have caught the problems earlier.

"Amid all the Congressional oversight, some of the worst problems plaguing the department’s fusion center efforts have gone largely undisclosed and unexamined," the report said.