NEW YORK — A U.S. senator is criticizing the director of Centers for Disease Control and Prevention for an apparent financial conflict of interest that the senator says may prevent the director from doing her job.

Dr. Brenda Fitzgerald became director of the Atlanta-based CDC in July, and was required to sell a range of stocks she owned, including for beer and soda companies, the tobacco company Philip Morris International, and a number of health care companies such as vaccine manufacturers.

"I've done everything that they've requested, in a timely manner as they've requested," Fitzgerald said Monday in an interview with The Associated Press. "My financial people tell me we have now sold all the stocks."

Brenda Fitzgerald, then-Georgia Department of Public Health commissioner, left, and Gov. Nathan Deal respond to questions about Ebola victims under treatment at Emory University Hospital on Oct. 16, 2014, in Atlanta. David Tulis / AP

But last week, Sen. Patty Murray wrote Fitzgerald saying she's concerned about unresolved financial holdings noted in Fitzgerald's ethics agreement with U.S. Department of Health and Human Services. The CDC is part of HHS.

The agreement notes Fitzgerald is unable to divest from certain investments that could prevent her from talking about cancer and prescription drug monitoring programs, wrote Murray, a Democrat from Washington.

"I am concerned that you cannot perform the role of CDC Director while being largely recused from matters pertaining to cancer and opioids, two of the most pervasive and urgent health challenges we face as a country," wrote Murray, the ranking Democrat on the Senate Committee of Health, Education, Labor, and Pensions, which oversees the CDC.

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She called on Fitzgerald to release more information and to meet with the committee about the issue.

Public health leaders have noted Fitzgerald has kept an unusually low profile since becoming CDC director. Fitzgerald says she's simply wanted time to learn about the agency, but also said she bowed out of an Oct. 5 Congressional hearing on opioids due to a financial conflict of interest.

Fitzgerald said her stock purchases had been handled by two financial management companies and that she hadn't been aware of particular holdings until they were raised to her by ethics compliance officials at HHS. She said her stock sales have been completed since the October hearing.

HHS and CDC officials did not provide a copy of Fitzgerald's ethics agreement to the AP, and did not respond to questions about Murray's concerns.

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CDC, the nation's top public health agency, is the only federal agency headquartered outside of Washington, D.C. It has nearly 12,000 employees, and about three-quarters of them are based in the Atlanta area.

Fitzgerald, 71, was a long-time obstetrician-gynecologist in the Atlanta area, a former major in the U.S. Air Force, and campaigned twice, unsuccessfully, as a Republican candidate for Congress in the 1990s. She led Georgia's state health department for six years before being tapped for the CDC job.

People who've met with her say that in small groups or personal meetings she can be gregarious, and she was a prominent spokesperson on health issues in the past.

But since Fitzgerald took office, she has skipped important public health meetings and bowed out of at least one Congressional hearing. For months, she declined nearly all media interviews, and was absent from the kind of flu vaccination promotions that traditionally star CDC directors.

Fitzgerald said she was traveling or had other scheduling conflicts during many of those events.