Updated

North Carolina authorities are searching for a missing pregnant Marine based at Camp Lejeune and due to give birth any day.

Maria Frances Lauterbach, 20, was reported missing Dec. 19 by her mother, who was the last person to speak with her, on Dec. 13. It is not clear why the disappearance wasn't made public earlier.

Her cell phone was found Dec. 20 near the main gate at Camp Lejeune. Lauterbach is with the 2nd Marine Logistics Group.

Investigators are calling her disappearance suspicious, saying her mother reported that Lauterbach was going to testify about an incident she witnessed on base.

"There are several findings and pieces of evidence that have been discovered that cause law enforcement to be concerned with the circumstances surrounding Maria's disappearance," the sheriff's department said in a news release.

The Onslow County Sheriff’s Department found Lauterbach's abandoned car Monday night, according to a report in the Jacksonville Daily News.

Lauterbach's blue 2006 Hyundai Sonata was found at the Jacksonville Bus Station.

Click here to read the report.

First Lt. Richard Ulsh, a public affairs officer with the 2nd Marine Logistics Group, verified that Lauterbach is on active duty. Marine Corps and U.S. Navy investigators are cooperating with the investigation, he said.

The Associated Press contributed to this report.