Port Isabel police have charged 28-year-old Luciano Gomez with sexual assault of a child.
According to investigators, Gomez first met the then 13-year-old in 2007 while the two were at the beach.
The two started dating and a year later the teen became pregnant.
Investigators told Action 4 News the relationship continued for another two years, when they left to Mexico and moved in with Gomez's mother.
In 2010, when the teen was 16, she returned to Port Isabel following an arguement with Gomez.
She was pregnant with her second child, also fathered by Gomez, but came back without her first born child.
Concerned over the toddler's safety, the teen's parents went to police to file a report.
Due to the girl's age at the time of her pregnancies, police filed a warrant for Gomez's arrest.
Earlier this month police located Gomez during a traffic stop in Laguna Vista, where a search revealed he had a warrant for his arrest.
He was taken into custody and is currently being held at the Cameron County jail.
Investigators told Action 4 News that he is a Mexican national.
U.S Immigration & Customs Enforcement (ICE ) agents have filed a detainer against him.
Police say at this time the 18-year-old mother has custody of her second child, however the eldest remains in Mexico with Gomez's mother.
Detectives say Cameron County District Attorney's office is reviewing the case.
Additional charges of continuous sexual assault of a child could be sought.