Alcon received a subpoena from the U.S. Department of Health and Human Services on September 23 requesting the production of documents relating to marketing practices, as well as the remuneration of healthcare providers.
The case involves the Alcon products Vigamox, Nevanac, Omnipred and Econopred, as well as surgical equipment.
Novartis revealed the case in a footnote to its third-quarter results and said Alcon was cooperating with the civil investigation.
(Reporting by Ben Hirschler. Editing by Jane Merriman)