Authorities have tracked down the Pennsylvania high school student missing with a 45-year-old family friend in Mexico, and the teen girl is on her way to being reunited with her family.

As CrimeOnline previously reported, Amy Yu, 15, of Allentown, disappeared on March 5 after Kevin Esterly allegedly signed her out of Lehigh Valley Academy Charter School, posing as her stepfather.

According to CNN, Yu’s family had previously suspected the teen and the married father of two were in a relationship, and had demanded he stay away from her.

Allentown Police reportedly said in a statement that Amy was found “unharmed and in good health.”

A passenger on a flight to Cancun notified authorities after he recognized a couple on the plane as the missing teen and her alleged abductor.

Frank Castrovinci told CNN that he observed the pair together and initially thought Yu was Esterly’s adopted daughter, before he saw them interacting.

“It seemed odd the way she was leaning up against him and how he was rubbing her leg and it seemed like his hand was quivering a little bit,” he said.

After Castrovinci landed, he recognized Yu and Esterly from a TV news report and contacted authorities.

After his arrest, US Homeland Security Investigations agents and the US Marshals Service escorted Esterly to Miami.

This is a developing story and will be updated as more information becomes available.

[Feature Photo: Amy Yu andKevin Esterly /Police Handout]