Delaware's Chief Medical Examiner, Dr. Richard Callery, has been suspended from his job amid an investigation into the drug-testing lab overseen by his office.

Department of Health and Social Services Secretary Rita Landgraf issued a statement late Friday afternoon saying Callery was suspended with pay on Tuesday, "pending completion of an internal human resources investigation."

That investigation is separate from the Delaware State Police investigation of drug evidence that was tampered with, switched or missing after having been submitted to the state's lab.

Secretary Landgraf did not go into detail in her statement about the internal investigation, but did say the office is continuing to cooperate with police in their investigation.

The Associated Press reports authorities have identified at least 21 cases going back to 2010 in which there are potential problems with drug evidence.

Landgraf says Hal Brown, Deputy Director of the Office of the Chief Medical Examiner, is currently in charge of the office's operations.