It was, the chief federal prosecutor in Manhattan said on Monday, “a case of inviting and paying for foxes in the henhouse.”

Three researchers at the New York University School of Medicine who specialized in magnetic resonance imaging technology had been working on research sponsored by a grant from the National Institutes of Health.

But, prosecutors charged on Monday, the three had their eyes on other business as well. They conspired to take bribes from a Chinese medical imaging company and a Chinese-sponsored research institute to share nonpublic information about their N.Y.U. work, according to the United States attorney’s office in Manhattan.

The defendants, all Chinese citizens, included Yudong Zhu, 44, of Scarsdale, N.Y., an associate professor in the school’s radiology department who was described by the authorities as “an accomplished researcher and innovator.” He was hired by the university around 2008 to teach and conduct research related to innovations in M.R.I. technology, the authorities said.