Commandant of the Marine Corps General Robert Neller testifies during a Senate Armed Services Committee hearing on the Marines United Facebook page on Capitol Hill in Washington, D.C., U.S. March 14, 2017. REUTERS/Aaron P. Bernstein

WASHINGTON (Reuters) - The number of victims who have come forward to investigators looking into a growing scandal involving some Marines sharing nude photos of women online has doubled to more than 20, an official from the Naval Criminal Investigative Service said on Friday.

The Marine Corps has been rattled by a scandal involving a private Facebook group called “Marines United” and its surreptitious distribution of explicit images of women in the armed forces - often with obscene, misogynist commentary.

NCIS has opened an inquiry into the matter, and senior lawmakers on Capitol Hill have denounced the actions.

NCIS supervisory special agent Curtis Evans told reporters that he expected the number of victims to increase further and had expanded the investigation to look at groups and websites other than “Marines United.”