FILE - In this Jan. 27, 2016, file photo, an Aedes aegypti mosquito known to carry the Zika virus, is photographed through a microscope at the Fiocruz institute in Recife, Pernambuco state, Brazil. (Felipe Dana/AP)

Federal regulators are auditing the District’s public health lab in response to botched Zika testing that erroneously provided negative results to at least nine pregnant women, D.C. Department of Forensic Sciences Director Jenifer Smith said Tuesday.

At an oversight hearing before a D.C. Council committee, Smith said officials from the Centers for Medicare and Medicaid Services (CMS) had visited the lab Monday and Tuesday to review its operations and investigate how the mistakes were made.

It is not clear what kind of disciplinary action regulators may take as a result of the fumbled virus testing. CMS oversees virtually all lab tests involving humans in the United States, ensuring that analysts comply with federal law, so loss of certification could shutter the public health lab until it can come into compliance.

Smith’s disclosure of the visits from auditors came after D.C. Council member Charles Allen (D-Ward 6) asked whether the botched tests could endanger the lab’s accreditation. She said officials who handle the Clinical Laboratory Improvement Amendments (CLIA) certification program had a “specific” concern about the Zika mishap.

“They are reviewing all of this paperwork, and I’m sure they will provide their perspective on this,” Smith said. “I think they will determine that we did not follow the protocol. I think it’s clear we did not follow the protocol, so there will be some type of — not action — but advice given as a result of that.”

Allen said after the hearing that any risk to accreditation was cause for concern, but that he remained optimistic that federal officials would not have to take such drastic steps.

“I think it speaks to how serious this is,” Allen said. “This audit will hopefully come back and show that DFS has taken all the steps necessary” to avoid loss of CLIA certification.

Such a loss would be a serious setback for the department, which has dealt with other accreditation problems in recent years. DNA forensic testing was halted for an extended period beginning in April 2015 — just three years after the opening of a new $220 million lab facility — because of questions about the quality of DNA analysis.

Anthony Tran, who discovered the testing mistakes late last year after he took over the public-health lab, said the attention from federal officials would not necessarily affect the lab’s certification, as long as the lab can show it has fixed the problems.

Interviews and public documents show that the debacle unfolded over a period of months last year during which the District lab was in a state of turmoil — understaffed, lacking permanent leadership, spread thin on competing projects and relying on new employees to test for the emerging public health threat in Zika.

Smith declined to speak to a reporter after her testimony, requesting that questions be submitted in writing through LaShon Beamon, a department spokeswoman.

“As we would expect, CMS inspectors arrived yesterday and left this afternoon to conduct a surveillance audit” of the test used to determine the possible presence of Zika, Beamon later said in an email. “As with all audits conducted of our laboratory, the auditing body will share their findings when they are finalized.”

Beamon would not answer specific questions about how the auditors learned about the problems or what the consequences for the lab might be, except to say that any action taken by CMS would not affect the department’s forensic division.

Officials at the Centers for Medicare and Medicaid Services did not immediately respond to requests for comment.

The Washington Post reported last week that D.C.’s public-health lab had produced erroneous results for nine and perhaps more pregnant women tested between July and December of last year for Zika, a mosquito-spread virus known to cause severe birth defects.

Those women’s results were initially reported as negative, but follow-up tests by the Centers for Disease Control and Prevention were inconclusive for eight of them and confirmed that one had contracted Zika, public-health officials said.

Lab officials said Tuesday that the mistakes had multiple causes, including incorrect use of the chemicals involved in the test and a bungled formula for analyzing the results that was entered in an Excel spreadsheet by a scientist who has since left the department.

The number of incorrect results from last year may rise, as retesting of samples from the D.C. lab is not complete. In addition to the impact on affected families, the city may face millions of dollars in legal claims, lawyers say.

Public health officials say they do not know how far along in their pregnancies the women were when they were tested or whether they have given birth. They said they have notified the subjects’ health-care providers so they can relay the information to the affected women.

Allen said Tuesday that lab officials should follow up with those providers to confirm the women had been told their test results were faulty.

Zika has spread to more than 60 nations and territories across the Western Hemisphere since the epidemic began in Brazil. Some babies of mothers infected with the virus have the severe birth defect known as microcephaly, a condition characterized by an abnormally small head and often an underdeveloped brain.

But researchers say problems stemming from infection may be less obvious and not show up until a year after birth or longer. They can include hearing loss, irritability, and cognitive, sensory and motor-skill difficulties.

That means the fallout in the District may not be felt for some time.

A December report by the Centers for Disease Control and Prevention found that 6 percent of women in the United States infected with Zika had a baby or fetus with at least one birth defect related to the virus.