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(KMOV) -- According to Jefferson County Sheriff Glenn Boyer, the teacher accused of having a sexual relationship with a student has been charged.

Teresa Engelbach, 21, has been charged with three counts of statutory rape and one count of statutory sodomy.

Engelbach's bond has been set at $25,000.

Arrangements have been made for Engelbach to turn herself in when she is released from an area hospital. She is being treated for an unknown illness.

The female teacher substituted in the Dunklin R-5 school district in Herculaneum.

Engelbach is accused of having sexual relations with a 14-year-old boy who's a student in the district.

Accused teacher, Teresa Engelbach

The teacher also allegedly bought the student expensive gifts including a phone, clothes, shoes, a laptop and a $750 paintball gun.

Sheriff Boyer says that the teacher had sexual relations with the boy on four occasions in the last six weeks.

According to Jefferson County Sheriff, Glenn Boyer, none of the alleged incidents took place on school property; he says they all happened in rural parts of the county.

The 14-year-old boy attended Senn-Thomas Middle School in Herculaneum.

He told a teacher about the relationship with Engelbach and the teacher told administrators.

According to the superintendent of the Dunklin R-5 school district, Engelbach has been a substitute in the district since last September and did substitute in the boy's class.

Students say that the teacher and student have known each other for years.

The school district and Division of Family Services notified investigators about the allegations on Tuesday.

The district has released a statement saying they are fully cooperating with the investigation.