March 16 (UPI) -- An Amber Alert was issued in Mexico Friday for a missing Pennsylvania teen who police believe disappeared with a 45-year-old man more than a week ago.
Amy Yu of Allentown was last seen March 5 with Kevin Esterly, police said.
Investigators say before they disappeared together, Esterly had signed the 16-year-old girl out of her high school 10 times since November without her parents' permission. Police also said Yu may have listed him as her stepfather on her school emergency contact list.
Officials believe the two may have maintained a secret relationship for months.
A criminal complaint filed by Esterley's wife said he withdrew $4,000 from her bank account before his disappearance, and added that unidentified personal family documents are missing.
Records indicate Esterly was told by police last month to stay away from the girl.
The Amber Alert posting in Mexico said, "We consider the teenager's integrity is at risk being that she could be a victim of a crime."
Authorities believe Esterly and Yu may be traveling in the man's car, a red Honda Accord with Pennsylvania license plates.