SAN DIEGO (AP) — A 14-year-old girl was found in the barracks at a California Marine Corps base last month, two weeks after her grandmother in San Diego reported she had run away from home, and a Marine was detained for questioning, officials said Monday.

The Marine has since been released to his command while federal law enforcement officials investigate, said Marine Capt. Charles Palmer of the 1st Marine Logistics Group at Camp Pendleton, about 40 miles (65 kilometers) north of San Diego.

It was unclear how the girl and the Marine came into contact before military police found her in the barracks during the daytime on June 28, Palmer said.

According to the San Diego Sheriff’s Department, her grandmother reported her missing on June 13 and told authorities she had run away from home four days earlier. The grandmother told the deputy who interviewed her that the girl had run away before but only for brief periods.

The teen's information was entered into multiple missing person databases, including the National Center for Missing and Exploited Children, the sheriff's department said.

After she was found on base, authorities returned the girl to her grandmother, according to the sheriff’s department.

Military officials say they could not release any other details, including the age or rank of the Marine. The case has been handed over to the Naval Criminal Investigative Service, the federal agency in charge of investigating Navy and Marine Corps criminal cases.

NCIS spokesman Jeff Houston said no one has been arrested or charged in the case. He said the Marine was detained for questioning and released back to his command. The sheriff’s department and the San Diego Human Trafficking Task Force are assisting the investigation.