ATLANTA (KABC) -- The Centers for Disease Control reports that lab workers at the headquarters in Atlanta were possibly exposed to materials that "may have contained" live Ebola virus.
The virus was on a sealed plate that was transferred from a high-level bio-safety lab to a lower level lab, according to a CDC statement.
On Tuesday, CDC officials discovered the virus might have been alive. The agency says it cannot rule out any possible exposure to the lab technicians. One technician is being monitored for 21 days. According to officials, the sealed plate was not supposed to be moved into the lab where the technician was working.
CDC spokeswoman Barbara Reynolds said in a statement there was no exposure outside the lab. The possible exposure is under internal investigation and was reported to the Secretary of Health and Human Services, Sylvia Burwell.
The lab has been decontaminated twice and the Ebola material was destroyed. Transfers from the lab the material came from are halted during the internal investigation.
Additional employees were notified, but are not required to be monitored. The statement did not say how many employees were notified.
"I am troubled by this incident in our Ebola research laboratory in Atlanta," CDC Director Dr. Tom Frieden said in a statement. "Thousands of laboratory scientists in more than 150 labs throughout CDC have taken extraordinary steps in recent months to improve safety. No risk to staff is acceptable, and our efforts to improve lab safety are essential -- the safety of our employees is our highest priority."
News of the technician's possible exposure to Ebola comes days after CDC Director Tom Frieden returned from West Africa, where an outbreak of the virus has killed thousands. Frieden said Monday that response to the outbreak has improved significantly in recent months, but the virus continues to spread in Monrovia, Liberia and Conakry, Guinea.
The Associated Press and ABC News contributed to this report.