SACRAMENTO, Calif. (MCT) — A prominent neurosurgeon at the University of California, Davis, was banned from performing medical research on humans after he and a colleague were accused of experimenting on dying brain cancer patients without university permission.

Dr. J. Paul Muizelaar, who earns more than $800,000 a year as chairman of the university’s department of neurological surgery, was ordered last fall to “immediately cease and desist” from any research involving human subjects, according to documents obtained by The Sacramento Bee.