The Pentagon has confirmed that US inspectors who have been carrying out an investigation at a Defence Department laboratory have found plague samples that may have been mislabeled. It is the latest development in a case that start in May when the military shared that it has accidentally sent live anthrax samples from Dugway Proving Ground research center in the Utah desert.

This caused the official to start an investigation to know how the military's secure labs take care of biological agents. Pentagon press secretary Peter Cook has confirmed that last month, inspectors from the Centers for Disease Control and Prevention (CDC) had found plague sample at the Army's Edgewood Chemical Biological Center in Maryland.

But the shocking part was that sample was not in a special containment area, where it should be. In fact, it was found in a freezer just outside. Cook was of the view, "Additional testing is being conducted to try and verify once and for all whether or not it was labeled correctly and placed in the right location".

Cook has raised concerns over the handling of equine encephalitis samples as well. Cook said that it is confirmed that there is no risk to workers or general public.