Alexandria Kaluzny, 25, turned herself in on Thursday morning to face charges over her affair with the pupil who she taught in the spring of 2017.

It's alleged this summer the pair romped three times, including at a state forest, and two times behind a garage.

The former student teacher at Jersey Shore Area Middle School in the US state of Pennsylvania was in her final term before graduating from Mansfield University, the chief detective investigating the case said.

Chief detective for Lycoming County William Weber said Kaluzny and the teen had sex "in her vehicle and at other outdoor locations".

Kaluzny made no statement as she faced seven felony charges including involuntary deviate sexual intercourse, statutory sexual assault and endangering the welfare of children.

She also faces charges of corrupting the morals, unlawful contact and sending obscene materials to a minor, criminal use of a mobile phone as well as one misdemeanour count of indecent assault.

Weber told reporters: "She was the teen's student teacher. There was no sexual contact while she was his student teacher.

"The first sexual contact is alleged to have occurred in the summer of 2017," after Kaluzny had left the school, he added.

Kaluzny and the teenage boy — now 15 — began exchanging messages on social media last summer, and their relationship soon became sexual, it's alleged.

Weber went on: "They met on numerous occasions that summer and continued throughout this summer."

The relationship only ended when a member of the teen's family went to the authorities after suspecting the pair were meeting illicitly.

School officials confronted the unnamed teen, but he denied anything was going on.

As recently as last month, it's claimed Kaluzny sent the teen "a picture of herself showing sexual conduct" according to court papers.

Assistant superintendent for the Jersey Shore Area District Kenneth J Dady Jr said in a statement: "During an investigation by law enforcement, it was determined that there was no inappropriate behaviour while she was a student teacher in our district."

He went on: "The individual also had appropriate clearances and was under the general supervision of district employees during her placement."

Kaluzny was briefly held at Lycoming County Prison in lieu of $75,000 (£57,370) before being released on supervised bail.