CROWN POINT | Police say a 15-year-old Crown Point girl has been missing for a week after her father told authorities that she already had left when he arrived to pick up his daughter at summer school at Crown Point High School on July 20.

The girl, Libby McHugh, is 5-foot-4 and about 108 pounds with green eyes and blond hair. She was last seen wearing a white tank top and dark shorts. She wears eyeglasses, but it is unknown if she currently has them.

Crown Point police said they didn't issue an Amber Alert for the girl because the case did not meet the criteria, which includes a child "believed to be abducted, and is in danger of serious bodily harm or death."

On Sunday, Thomas McHugh told police his daughter called the father of her friend, and said she was calling from Chicago, where she was with two subjects in a blue Chevrolet Malibu with Ohio license plates. McHugh's ex-boyfriend had been contacted by her and told the same information, officials said.

Crown Point Detective Larry Scott discovered the call actually came from a pay phone in Indiana Dunes State Park. But when officials at the park were contacted, no one was found near the phone.

Police have sent McHugh's description to all Indiana law enforcement agencies through a statewide system. She also has been entered into the nationwide National Crime Information Center database as a missing juvenile.

Thomas McHugh said he doesn't have any information as to his daughter's whereabouts, and Crown Point police said his attempts at contacting her through friends have been unsuccessful.

Scott has been visiting her hangouts and friends. Security camera footage at the high school is being reviewed, but so far McHugh has not been seen on camera leaving the building.

In a statement, Crown Point Police Chief Pete Land said Libby McHugh is being treated as a missing person case, not a runaway.

Anyone with information should call Scott at (219) 663-2131, ext. 171, or they can leave an anonymous message on the Police Department's crime line at (219) 663-2131, ext. 265.