President Donald Trump's pick to head the nation's Indian Health Service was hit by a bombshell report Friday that suggested he misrepresented his prior work experience to a Senate committee.
And a senator on that committee said later Friday that the story about Trump nominee Robert Weaver has raised "very serious concerns" that he now wants answers to.
The Wall Street Journal quoted multiple former workers at what was once known as St. John's Regional Medical Center in Joplin, Missouri, who called into question Weaver's claims to the Senate Indian Affairs Committee that he had worked in supervisory and management positions at that hospital.
Weaver, 39, worked at St. John's from 1997 to 2006, according to his resume. His nomination to run the federal agency that provides health services to American Indians and Alaska Natives is pending before the Senate.
"I don't recall that name whatsoever," Augusto Noronha, the hospital's chief financial officer from 1999 through 2005, told the Journal when asked about Weaver.
A former controller of the hospital told the newspaper, "I've never heard that name before."
Another executive said he remembered "a subordinate named Rob Weaver who registered E.R. patients, gathered insurance information and collected copays, and who eventually supervised a few other patient-registration workers," according to the Journal.
Weaver, who is a member of the Quapaw tribe of Oklahoma, did not return a call seeking comment from CNBC made to one of his companies, RWI Benefits in Oklahoma.
The Journal reported that Weaver told the paper that all questions about his resume should be put to the federal Health and Human Services Department, which oversees the Indian Health Service.
But Weaver also said, "There's a lot more to this story than what you are apparently being told."
An HHS spokeswoman told the Journal that "any suggestion Mr. Weaver is unqualified to run IHS is a pure act of character assassination."
Sen. Tom Udall, D-N.M., in an emailed statement sent to CNBC after this story was published, said, "Mr. Weaver's responses on the Committee's formal questionnaire, his answers to my questions in person, and the Wall Street Journal article raise a number of very serious concerns for me."
"After our meeting in December, I asked Mr. Weaver to respond in writing to a number of detailed follow-up questions," Udall said.
"I look forward to reviewing his answers to those questions, as well as the updates and corrections he pledged to make on the materials he originally submitted to the Committee, when I receive them."
HHS, in response to a request for comment from CNBC, forwarded an email written by St. John's former chief operating officer, Dottie Murphy, that had been sent to Weaver on Thursday.
Murphy's email said that she had worked at the hospital from 1987 to 2002. During the time she had worked with Weaver she had been director of the emergency department as well as vice president of patient care services, the email said.
"Mr. Weaver served in various leadership roles which were within my line of authority," Murphy wrote. "Mr. Weaver possessed great leadership skills and provided oversight for responsibilities including great communication, organizational skills, problem solving skills as well as the ability to work well with others. These skills served him well in his various roles which required oversight of many other team members."
"When Mr. Weaver started at our facility he was a young man who was only a year out of high school," Murphy wrote. "He rapidly became a person others respected and sought out for advice and help dealing with operational issues within the facility. In my time working with Rob Weaver, I was also impressed with his tenacity and willingness to take on new assignments and duties which he performed exceptionally well.
"I fully believe Mr. Weaver is qualified to lead Indian Health Services. I give him my full support," Murphy wrote.