A “secretive” Drug Enforcement Agency (DEA) unit is funneling information to authorities to help them launch criminal investigations of Americans, Reuters reports. The cases rarely involve national security issues; however, documents show that federal agents are taught to cover up the “investigative trail,” or where the information originated.

The DEA is funneling information from “intelligence intercepts, wiretaps, informants and a massive database of telephone records to authorities across the nation to help them launch criminal investigations.” Covering up the origin of the information, some experts say, violates a defendant’s right to a fair trial.

“If defendant’s don’t know how an investigation began, they cannot know to ask to review potential sources of exculpatory evidence – information that could reveal entrapment, mistakes or biased witnesses,” the report states.

Nancy Gertner, a Harvard Law School professor who served as a federal judge from 1994 to 2011, told Reuters that the practice sounds more troubling than the recent revelation that the National Security Agency has been collecting phone records. While NSA is focused primarily on stopping terrorists, the DEA targets primarily drug dealers and “common criminals.”

The DEA unit distributing such information is known as the Special Operations Division (SOD). The unit is comprised of several partner agencies, including the FBI, CIA, NSA IRS, and Department of Homeland Security. Much of SOD’s work is classified, “Law Enforcement Sensitive,” which keeps the information confidential.

Two senior DEA officials spoke to Reuters on condition of anonymity, saying that the process of trying to “recreate” an investigative trail is “not only legal but a technique that is used almost daily.” However lawyers have said government efforts to conceal the circumstances under which a case began would be “indefensible, and blatantly unconstitutional.”

Alisha is a writer and researcher with Ring of Fire. Follow her on Twitter @childoftheearth.