Authorities are investigating a possible teacher-student relationship at Hampshire High School, according to Kane County court documents.
Authorities have obtained search warrants for the smartphones of an 18-year-old male student from Gilberts and a 23-year-old female teacher, records show.
According to the search warrant, the teacher performed a sex act on the student at least twice in late 2013 and provided him with test answers.
The Daily Herald is not naming the teacher because she has not been charged with a crime.
According to the police summary in support of obtaining the search warrant, a high school resource officer interviewed a friend of the male student in late April after hearing of the situation from Hampshire High School Principal Brett Bending.
The student said he saw the teacher's face on a Snapchat message and his friend said he met the teacher at a restaurant on Route 20 in Hampshire, where they "made out" in the student's car, according to the search warrant.
The student wanted to have sex, but the teacher said "Not until you turn 18," the friend told the resource officer, according to the search warrant.
Police also interviewed the teacher, who agreed to allow authorities to examine her phone but admitted to erasing text messages with the student, in part because one of the messages from him began with "Hey babe," according to the search warrant.
When asked if there was anything inappropriate between her and the student, she said there "could be" and then said she wanted to speak to an attorney, according to the warrant.
A message left Wednesday with Bending was not immediately returned.
Allison Strupeck, Community Unit District 300 spokeswoman, said the first-year teacher has been placed on administrative leave. Strupeck added the district would not comment further.
Hampshire Police Chief Brian Thompson could not immediately be reached for comment, but his office did issue a statement confirming the investigation into a possible student-teacher relationship.
"We will continue to work closely with school officials and the state's attorney's office during the investigation. No further information is available," part of the statement read.
The warrant was issued to investigate a possible offense of aggravated criminal sexual abuse. Authorities are targeting text messages, phone calls, photos, videos and content from social media applications.
Because the allegations are that the teacher was in a position of trust and authority, the felony is punishable by anywhere from probation to seven years in prison.