The CIA and the military special forces have quietly expanded the role of private contractors, including Blackwater, to include their involvement in raids and secret paramilitary operations in Afghanistan, Pakistan and Iraq, four current and former U.S. military and intelligence officers tell ABC News.
American law specifically prohibits the use of private soldiers or mercenaries in combat, according to Jonathan Turley, a professor of public interest law at George Washington University.
"The United States Congress has never approved the use of private contractors for combat operations," Turley told ABC News in an interview to be broadcast tonight on ABC World News with Charles Gibson.
CIA officials acknowledge that two private contractors were killed in Afghanistan in 2003 when they and other members of a CIA paramilitary team were in a firefight with Taliban fighters on a remote road.
In another case, in 2006, 12 Blackwater "tactical action operatives" were recruited for a secret raid into Pakistan by the U.S. military's Joint Special Operations Command, according to a military intelligence planner. The target of the planned raid, code-named Vibrant Fury, was a suspected al Qaeda training camp, according to the planner, who said he did not know the outcome of the mission.
In Iraq, a high-ranking U.S. Army officer told ABC News, Blackwater personnel have been used in military operations that "are supposed to include U.S. soldiers but often end up with the Blackwater people on their own."
The New York Times reported Friday that such raids against Iraqi insurgents were conducted "almost nightly" between 2004 and 2006, and it quoted several Blackwater guards as saying "the operations became so routine that the lines supposedly dividing the Central Intelligence Agency, the military and Blackwater became blurred."
The Washington Post today quoted former government officials as saying Blackwater's actions included "active participation in raids overseen by CIA or special forces personnel."
American officials reject the term "mercenary," but others say the term applies if the role of private American contractors has been so significantly expanded beyond their previously known assignments in security and logistics.
"If contractors have been sent on true combat missions, missions where they are supposed to kill and engage the enemy, then they are by every definition of the term mercenaries," said Professor Turley.
"To have such a force without allowing Congress to approve it would be considered a very serious offense to our Constitution," said Turley.
A CIA spokesperson, George Little, acknowledged the use of contractors "in roles that complement and enhance the skills of our workforce, just as American law permits."
Little said "it's the way things actually work in the real world," and he stressed that CIA officials always retained "decision-making authority and bear responsibility for results."
"CIA does not use Blackwater to perform our core missions of collecting intelligence, performing analysis or conducting covert operations," said Little.
A U.S. government official told ABC News the private contractors "don't kick down doors" but only fulfill a "security role" on certain CIA missions.
The new CIA director under the Obama administration, Leon Panetta, has continued a "rigorous look" at the use of contractors and a "thorough review" of Blackwater's contracts.
Said Little, "Earlier this year, Director Panetta ordered the end of one Blackwater contract and the transition of those activities to government personnel. In addition, he ordered a review of all Blackwater contracts."
"At this time," said Little, "Blackwater is not involved in any CIA operations in other than a security or support role."
Pentagon spokesman Geoff Morrell said the allegation that private contractors were used in combat situations by the American military was "bogus, nothing more than a wild and unsubstantiated allegation." He said there was no evidence that the military had ever contracted with Blackwater for such missions.
Morrell did not respond to specific questions about the top-secret Vibrant Fury operation in 2006 that allegedly recruited Blackwater operatives.
"If you have a team of private contractors who are going into Pakistan with the approval of the United States government to engage in combat, then you have very serious international and domestic problems," said Professor Turley.
Blackwater, now re-named Xe, has a "select" program within its operation that helped to staff some of the expanded and more difficult roles in the two war zones, according to U.S. military officials, former U.S. intelligence officers and a person with knowledge of Blackwater operations.
A 2007 on-line recruitment advertisement for the Blackwater USA select program described the openings as positions in a "Mobile Security Contract in support of a U.S. government agency."
Candidates were required to be able to maintain a Top Secret clearance and have "one year of experience in Iraq, Afghanistan or other High Threat Environment."
A U.S. Army officer who ran human intelligence collections activities in Afghanistan in 2003, Tony Shaffer, says he never worked directly with Blackwater personnel but frequently encountered them in secret operations run by the military and the CIA.
"I actually met with the CIA and Blackwater operatives who were working together, totally hand in glove, to conduct operational planning and support of their objectives, which are paramilitary operations along the border," said Shaffer, then a Major but now a Lieutenant Colonel who teaches at the Center for Advanced Defense Studies.
"The idea was to bring to bear additional resources for specific special operations missions," he said. "The purpose for that, in my judgment, may have been to avoid some level of oversight."
In the case of Operation Vibrant Fury, military personnel say the decision to request Blackwater personnel came after a request for military "tier one" operatives was denied.
A spokesperson for Blackwater said the company was unaware of any operation with the code name Vibrant Fury.
The mission was to raid, destroy and kill al Qaeda members at a camp in Pakistan where guards for Osama bin Laden and Ayman al Zawahiri were believed to be training, according to the military planner.
A second person briefed on the operation confirmed Blackwater agreed to provide operatives for the military special forces.
The commanders of the elite special forces, then called Task Force 373, decided to solicit help from Blackwater, said the planner, after military superiors said the men could not be spared from Iraq.
The request to Blackwater was met on Oct. 31, 2006, according to the planner.