Two neurosurgeons from the University of California, Davis have been banned from performing medical research on humans after they allegedly experimented on three patients without university permission, the Sacramento Bee reports.

The university ordered the scientists to "immediately cease and desist" from any research involving human subjects last fall, when the two doctors introduced bacteria into the open head wounds of three patients. The Sac Bee reports on documents that allegedly show the surgeons obtained consent of three terminally ill patients with malignant brain tumors to introduce bacteria into their open head wounds in hopes that it might save their lives.

However, the university has found that two of the three patients developed sepsis and died.

One of the doctors, J. Paul Muizelaar, 65, holds a prestigious position as chair of the Department of Neurological Surgery. Rudolph Schrot, 44, worked under Muizelaar as an assistant professor and neurosurgeon.

Muizelaar, however, doesn't believe he did anything wrong.

"And I understand it," Muizelaar reportedly said, "there are people who blatantly break the rules that endanger all of their research programs. We certainly didn't blatantly trample any rules."

Research on humans is tightly controlled in the U.S., requiring a thorough approval process, which it is alleged the neurosurgeons failed to follow. Alleged violations involving experimental drugs or devices are handled by the U.S. Food and Drug Administration, but the federal agency has not notified UC Davis whether any punishment will be levied on the school. The University "self-notified" the FDA about the doctors' failures to secure proper approval for their experimental surgeries.

The incident threatens not only the doctors' reputations but also the reputation of the medical school.

UC Davis, which has a highly ranked medical school, received $130 million in federal funding in 2011 from the National Institutes of Health.

