The Navy has taken an active-duty Marine stationed at Camp Pendleton into custody after a missing 14-year-old girl was found in the barracks, CBS News Los Angeles's Matthew Rodriguez reports.

In a statement obtained by CBS News Friday, a spokesperson for the base north of San Diego says the Marine was detained "for questioning by Naval Criminal Investigative Services after a female minor was found in the barracks on June 28, 2023, as seen on a number of social media posts on and after July 2, 2023.

"This command takes this matter and all allegations very seriously," the statement continued. "This incident is under investigation and we will continue to cooperate with NCIS and appropriate authorities."

It was unclear whether the Marine was still being held.

Rodriguez cites the San Diego County Sheriff's Department as saying the teenager ran away from home on June 9. At first, her grandmother waited to call police since her granddaughter had run away before but always returned quickly. 

But after several days passed, the grandmother called deputies and reported her missing on June 13. 

The teen was found in late June inside Camp Pendleton and returned to her grandmother, the sheriff's department said.

"Since Camp Pendleton is federal property, the Naval Criminal Investigative Services (NCIS) is handling the investigation," the sheriff's department added. "The Sheriff's Department and the San Diego Human Trafficking Task Force are supporting NCIS with the investigation."

The teen's family is accusing the Marine of raping the 14-year-old and the Navy of trying to cover it up.

In a TikTok video posted Thursday, a woman identifying herself as the girl's aunt, Casaundra Perez, says her niece is under the age of 18 and has learning disabilities. Perez says the teen went missing June 10, a day later than San Diego authorities reported, and was found in the barracks on June 27, a day earlier than other media reports stated.

"She had been sold to a soldier for sex," Perez asserted. "The military is trying to cover it up ... and place (a) majority of the blame on her. However, the reality is the whole facility allowed this to happen. The security looked her in the face and allowed this man to bring a minor onto base, where he then proceeded to have sex with her. ... Our family is worried about retaliation form the military and the man that has trafficked my niece. We believe they could be working together and covering this up and that the military is only trying to protect their property."

The Navy hasn't responded directly to the rape allegation.