Child sex-assault charges are dropped against Camp Pendleton Marine Avery L. Rosario who was accused after a 14-year-old girl was found in his barracks

The child sexual assault charges have been dropped against Camp Pendleton Marine Avery L. Rosario.

Private First Class Rosario was charged by military prosecutors last year after the teenage girl, who had been missing for 18 days, was found at Camp Pendleton.

The unnamed girl went missing on June 10 and her family has claimed she was sold to a Marine stationed at the base as a sex slave. 

But Rosario's defense said he met the girl on Tinder and her profile said she was 21 years old.

The charges against Rosario have now been dropped, just one week before his general court-martial was expected to start, NBC San Diego reports. 

Private First Class Rosario (second from right) was charged by military prosecutors last year after the teenage girl, who had been missing for 18 days, was found at Camp Pendleton

The unnamed girl went missing on June 10 and her family has claimed she was sold to a Marine stationed at the base as a sex slave

Rosario, seen handcuffed in July, claimed he met the girl on Tinder and that her profile said she was 21 years old

He entered a plea agreement, which saw military prosecutors re-refer him to a special court martial for a charge of 'breach of restriction' for leaving the base without permission on June 27 to meet the teenager using a privately owned vehicle.

At the time, Rosario had been 'placed on restriction' after being tested positive for THC, the active ingredient in marijuana, his attorney confirmed.

He has now been released from confinement after serving more than twice the maximum sentence for breach of restriction, which would only be one month. 

Rosario was sentenced to a reduction of rank forfeiture of two-thirds of pay for one month - in line with the punishment for breach of restriction. 

As part of the plea agreement, Rosario will be discharged from the Corps, which could take up to 120 days.

Rosario matched with the girl on Tinder on June 26 after she created a profile under the pseudonym 'Kayla', his lawyers told an Article 32 hearing, which is the military equivalent of a civilian preliminary court hearing.

Rosario's lawyers emphasized Tinder is for casual sex. They said Rosario and the girl began messaging and the teen suggested they move their conversation to Instagram and even proposed they get a hotel room.

Rosario claimed he drove to pick up the girl on June 27 and the two had consensual sex at the barracks.

The next day, Rosario left her at the barracks, where she was eventually discovered.