Investigators have identified 15 active-duty service members who may have engaged in criminal activity related to the Marines United nude photo sharing scandal, the head of the Naval Criminal Investigative Service told reporters on Friday.

Separately, NCIS has identified 29 Marines who could be disciplined for non-criminal behavior online; and two Marines have received non-judicial punishment for disparaging their commander on social media, officials said.

NCIS has more than 100 people investigating allegations that service members and veterans harassed women online and shared nude pictures of female troops, veterans and civilians on the Marines United Facebook page.

Although the original Facebook group had more than 30,000 members, only a few of them had access to the pictures, and fewer still may have broken the law, NCIS Director Andrew Traver said at a meeting with reporters Friday.

So far, NCIS has identified 27 people who may have been involved in "some type of criminal activity" by posting pictures, Traver said. Of those people, 14 are active-duty Marines and one is an active-duty sailor, he said.

It is too early to say what kind of punishments the Marines and sailor could face, said Marine Corps spokesman Maj. Clark Carpenter.

Marine Corps Times reported on Thursday that several of the nude pictures of women shared on Marines United are now being sold on a website associated with the Russian mafia. Traver declined to comment about any ongoing investigations.

To counter the online harassment of women, the Marine Corps has updated its social media policy to clearly state that such activity is illegal. The Corps is also requiring commanders to notify NCIS within 24 hours if they determine that social media misconduct rises to the level of criminal behavior.

A Marine Corps "fusion cell" is reviewing the cases of the 29 Marines flagged for possible online misconduct that was not serious enough to be considered criminal, officials said. The cell will decide whether to refer any of those Marines to their commands for disciplinary action.

Meanwhile, two Marines with 2nd Battalion, 4th Marines at Camp Pendleton, Calif., have received administrative punishment for their comments on the social media page United States Grunt Corps, officials said. The Marines were taking part in an online conversation about women when they insulted a senior enlisted member of their chain of command.

On Wednesday, the Marines were demoted by one pay grade, issued 45 days of military restriction and 45 days of punitive duties, their battalion commander, Lt. Col. Warren Cook, said in a statement. The Marine Corps has not released any identifying information about them, but Marine Corps Times was able to independently confirm that one was a noncommissioned officer and the other a junior Marine.

"To me, this a good news story because now we have commanders taking action to police up their people and their online behavior, which is what we want," Assistant Commandant Glenn Walters said on Friday.