BOSTON — One pharmacist said she quit because she was worried that unqualified people were helping prepare dangerous narcotics for use by hospitals. A quality control technician said he tried to stop the production line when he noticed that some labels were missing, but was overruled by management. A salesman said he and his colleagues were brought into the sterile lab to help out with packaging and labeling during rush orders, something they were not trained for.

They all used to work at Ameridose, a drug manufacturing company with many of the same owners as the New England Compounding Center, the pharmacy at the center of a national investigation into a meningitis outbreak now in 12 states.

State and federal health officials say they have no reason to believe that Ameridose sent out contaminated products, and have not recalled any. But regulators asked the company on Wednesday to suspend production to allow them to conduct an on-site investigation, because their inquiry “includes concerns for quality and safety across the corporate entity,” the Massachusetts Department of Public Health said.

Paul Cirel, a lawyer representing Ameridose, declined to discuss the statements made by the former employees. “What some anonymous, maybe disgruntled, ex-employees say to you that is not said to us by the F.D.A. or any regulator, I just can’t go there right now,” he said. “If it becomes a claim that a regulator puts to us, then we will address it.”