A biology lecturer at the City University of New York was arrested Friday on fraud and corruption charges, federal and state investigators said, for teaching unauthorized health care classes and selling students fake certificates of completion.

He had established “his own fraudulent trade school” at Medgar Evers College in Brooklyn, said Catherine Leahy Scott, the New York State inspector general.

Mamdouh Abdel-Sayed, a full-time tenured lecturer at Medgar Evers, offered classes on medical techniques, such as CPR and administering EKGs, that he was not authorized to teach, investigators said. They said he pocketed the fees and printed certificates on college letterhead from his computer. He encouraged students to use the certificates when applying for jobs — sometimes successfully — at hospitals and elsewhere, investigators said.

He often held the classes at Medgar Evers on evenings or weekends when the college was less crowded, officials said.