A pen that a Johns Hopkins gynecologist who secretly videotaped patients wore around his neck drew suspicion from another doctor, the Baltimore Sun reported.
The doctor alerted hospital officials.
The pen contained one of the cameras Dr. Nikita Levy used to record his patients, investigators said.
Levy was fired earlier this month, then killed himself last Feb. 18 after the allegations came out.
Several lawsuits have been filed against Johns Hopkins.