ST. PAUL  — A legislative audit shows overtime pay at one of the state government’s largest agencies has reached $59 million in the past three years.

The report shows employees at the Minnesota Department of Human Services accumulated more than 1 million hours of overtime between July 1, 2013 and June 30, 2016.

The agency has struggled to maintain staffing at the state’s psychiatric hospitals. In one case, a counselor at the Minnesota Security Hospital in St. Peter worked 8,129 extra hours since 2013 and was paid nearly $295,000 in overtime.

The Star Tribune reports state officials attribute the soaring overtime to a combination of staff vacancies and more patients requiring one-on-one staffing.