The New York Time’s is reporting that Columbia University’s Kreitchman PET Center is in trouble for injecting mental patients involved in brain studies with dangerously impure imaging drugs.

To perform a PET scan, patients must first be injected with a drug called a radiotracer. According to The Times, such drugs are considered very safe, but degrade quickly. As such, many labs make these drugs themselves, following strict protocols which regulate the allowable radiation levels and the purity of the drugs. Drugs that contain impurities can have effects in the body that are unpredictable.

Kreitchman PET Center, located in Manhattan, New York City, is considered the nation’s leader in the use of positron emission tomography, or PET, for psychiatric research, according to The Times. Pharmaceutical companies provide millions of dollars to the center every year to study drug actions and the biology of brain disorders.

According to The New York Times, a Food & Drug Administration (FDA) investigation found that researchers at the Kreitchman PET Center routinely injected mental patients with drugs that contained potentially dangerous impurities, repeatedly violating agency regulations over a four-year period. The FDA first wrote to Columbia in December 2008, citing lax internal quality control and sloppy procedures for formulating drug injections. It warned that: “Failure to promptly correct these violations may result in legal action without further notice.”

Then in January 2010, FDA investigators returned and found that many of the Kreitchman PET Center’s lab practices had not changed. The agency cited a long list of specific violations, including one instance in which the staff hid impurities from auditors by falsifying documents, The Times said. One former lab worker told The Times that the FDA “raided the place like it was a crime scene, seizing hard drives.”

According to The Times, during its last investigation, which took place from Jan. 5 to Jan. 21, the FDA cited six categories of violations. Since 2007, “at least 10 batches” of drugs had been “released and injected into human subjects” with impurities that exceeded the level the lab had agreed to set, investigators said. At least four injections “had impurity masses that more than doubled the maximum limit implemented.” Agency investigators also found a forged document, a hard copy record that had been altered to hide a drug impurity that showed up clearly in the computer records, The Times wrote

The FDA did not make its investigation public.

According to The New York Times, Columbia University has since quietly suspended research at the Kreitchman PET Center and reassigned top managers there as a result of an FDA investigation.