Margaret Low Smith, vice president of National Public Radio, said NPR would remove “The Infinite Mind” from its satellite radio service next week, the earliest date possible. Ms. Smith said that had NPR been aware of Dr. Goodwin’s financial interests, it would not have broadcast the program.

Sarah Alspach, a spokeswoman for GlaxoSmithKline, said, “We continue to believe that healthcare professionals are responsible for making disclosures to their employers and other entities, in this case National Public Radio and its listeners.”

“The Infinite Mind” has won more than 60 journalism awards over 10 years and bills itself as “public radio’s most honored and listened to health and science program.” It has more than one million listeners in more than 300 radio markets. Mr. Lichtenstein said that the last original program was broadcast in October, that reruns have been running since and that “the show is going off the air.”

Image Dr. Frederick K. Goodwin in 2001 during taping of The Infinite Mind, his public radio program. Credit... Don Hogan Charles/The New York Times

The program has received major underwriting from the National Institutes of Health and the National Science Foundation, both of which have policies requiring grantees to disclose and manage conflicts of interest. Mr. Grassley wrote letters to both agencies asking whether disclosure rules were followed for the grants. Spokesmen for both agencies said they were cooperating with the investigation.

Mr. Grassley is systematically asking some of the nation’s leading researchers and doctors to provide their conflict-of-interest disclosures, and he is comparing those documents with records of actual payments from drug companies. The records often conflict, sometimes starkly.

In October, Mr. Grassley revealed that Dr. Charles B. Nemeroff of Emory University, an influential psychiatric researcher, earned more than $2.8 million in consulting arrangements with drugmakers from 2000 to 2007, failed to report at least $1.2 million of that income to his university and violated federal research rules. As a result, the National Institutes of Health suspended a $9.3 million research grant to Emory, and Dr. Nemeroff gave up his chairmanship of Emory’s psychiatry department.