Washington: The US Marine Corps is looking into allegations that an unknown number of potential Marines, as well as current and former service members, shared naked and compromising photos of their colleagues on social media, Marine officials said on Sunday.

The allegations were first reported by The War Horse and published on Saturday through the website Reveal. The author, a Marine veteran and Purple Heart recipient, has received numerous death threats since the article was first published. It is unclear how many people are involved in the scandal and how many photos were posted online.      

According to the report, the photo sharing began less than a month after three enlisted women were assigned to a Marine infantry unit for the first time in the corps' history, a move that has been hotly debated within the military, with one female Marine officer arguing in a prize-winning essay that it would open the way to increased sexual harassment, a view rejected by other Marines.

The War Horse's report focuses on one Facebook group with more than 30,000 members called Marines United. In January, a link to a shared hard drive containing photos of numerous female Marines in various states of undress was posted to the group, according to The War Horse's report. The hard drive contained images as well as the names and units of the women pictured. Many of the photos were accompanied by derogatory and harassing comments.

The shared drive has since been taken offline and the Naval Criminal Investigation Service (NCIS) is investigating "incidents related to the Marines United group", said Captain Ryan Alvis, a Marine Corps spokesman.

The chairman of the House of Representatives' Armed Services Committee, Republican Mac Thornberry of Texas, and the panel's senior Democrat, Adam Smith of Washington state, separately called for a complete investigation.

"Degrading behaviour of this kind is entirely unacceptable," Mr Thornberry said. "I expect the Marine Corps to investigate this matter fully with appropriate consequences for those who willingly participated."

Photos of Marine Lance Corporal Marisa Woytek were taken from her Instagram account and posted to Marines United multiple times in the past six months without her consent.

"Even if I could, I'm never re-enlisting," Corporal Woytek said. "Being sexually harassed online ruined the Marine Corps for me, and the experience."

Corporal Woytek said she was alerted to the hijacked photos by others on social media and was shown the comments that accompanied them. She said that many of the comments included allusions to sexual assault and rape.

Many of her female colleagues have experienced similar incidents, she said, and added that they been reluctant to speak out for fear of retaliation from the group's thousands of members. With The War Horse's report on Saturday, Woytek said that she and others "have a voice now".

On Sunday, the Marine Corps' highest-ranking officer, commandant General Robert Neller, did not directly address the investigation of Marines United.

"For anyone to target one of our Marines, online or otherwise, in an inappropriate manner, is distasteful and shows an absence of respect," he said in a statement. "I expect Marines to give their all to be the best human beings, teammates, and Marines possible."

Washington Post