June 4, 2015 — The U.S. Justice Department has subpoenaed three manufacturers of medical scopes linked to several recent outbreaks of antibiotic-resistant “superbugs,” USA Today reports.

According to two anonymous sources close to the investigation, the Justice Department is seeking thousands of pages of documents from Olympus Corp., Pentax Medical, and FujiFilm Holdings Corp.

A subpoena was also delivered to Virginia Mason Medical Center in Seattle, where 11 people died after developing serious infections transmitted on contaminated scopes.

An attorney for the hospital said the Justice Department wanted information and communications related to Olympus duodenoscopes dating back several years, according to the Los Angeles Times.

Virginia Mason has filed a lawsuit accusing Olympus of failing to provide adequate cleaning instructions for the scope.

Last week, financial documents (PDF) issued last month by Olympus revealed that the company had been subpoenaed by officials at the Justice Department back in March. However, the broader reach of the investigation and subpoenas to Virginia Mason were not reported until now.

As antibiotic-resistant infections have become an increasing problem in hospitals, national attention has turned to the risk of disease-transmission on contaminated medical scopes. Earlier this year, the FDA warned that duodenoscopes have complex mechanisms that are very difficult to sterilize between uses.