St. Paul police are investigating an alleged sexual assault at Crossroads Elementary School involving a male staff member and a high school student volunteer.

Police received a report on Sept. 17 about the incident that allegedly occurred sometime this past January, said Sgt. Mike Ernster, a police spokesman.

The case remains under investigation, and no arrests have been made.

According to police, a 17-year-old female student from Cretin-Derham Hall was at Crossroads for a school service project. An adult male staffer at Crossroads allegedly had sexual contact with the student.

St. Paul Public Schools issued a statement Friday acknowledging the investigation and deferred questions to the police. No Crossroads students were involved in the alleged misconduct, school officials said.

“Following district protocol, the employee in question was immediately placed on administrative leave and we are actively working with the Saint Paul Police Department,” the district statement said.

Neither police nor the school district divulged information about the staffer’s position at the school, his tenure with the district or how he may have come in contact with the girl.

Ernster said many details of the case remain under investigation.