BUHL — Investigators and former and current employees of Mesabi Academy are raising concerns about conditions at Minnesota’s largest private correctional facility for boys and whether it’s following the proper channels in reporting allegations of maltreatment.

The Minnesota Department of Corrections houses and treats up to 123 boys at Mesabi Academy in St. Louis County. The boys are sent to Mesabi from juvenile courts, social service agencies and parents.

Last spring, Caroline Mattson informed her superiors that three boys had told her they had been sexually abused by an employee. Mesabi began an internal investigation, prompted either by that report or another.

But academy leaders did not tell St. Louis County authorities about the allegations, a decision that avoided outside scrutiny and may have evaded state law. Six months later, in October 2015, county officials learned of the alleged incidents and began their own investigation.

County officials recently closed its six-month investigation into allegations of sexual abuse and maltreatment, saying they had insufficient evidence to substantiate the accusations, according to APM Reports, a unit of American Public Media. Investigators also determined that academy staff didn’t report some of the allegations to law enforcement or child protection officials.

Current and former staffers at Mesabi Academy said in dozens of interviews that the facility routinely conducts internal investigations and discourages employees from reporting problems to outside law enforcement, according to APM Reports.