In a statement Wednesday, the New England Compounding Center said it was working closely with the state Department of Public Health and other regulators to identify the source of infection.
The company said that immediately after it was notified about the infections it initiated a voluntary recall Sept. 26.
Health officials say the outbreak has sickened 26 people in five states who received steroid injections. Four people have died. Eighteen of the cases are in Tennessee, where a Nashville clinic received the largest shipment of the steroid from the Framingham-based company.
The Massachusetts health department said it is collaborating with federal regulators and other states on the investigation. It confirmed the New England Compounding Center voluntarily surrendered its license to operate and has recalled the suspected steroid medication along with all similar medications it produced. The department said there have been no cases of the deadly form of meningitis in Massachusetts.