CHICAGO — The Archdiocese of Chicago is investigating allegations that a suburban priest sexually abused children 25 years ago.

Cardinal Blase Cupich wrote a letter to parishioners on Saturday saying he asked the Rev. David Ryan to “step aside from ministry” after the archdiocese received the allegations.

Ryan, pastor at St. Francis de Sales Catholic Parish in Lake Zurich, has been “directed to live away from the parish” during the investigation and “is fully cooperating with this direction,” Cupich said in the letter.

The abuse allegations were from when Ryan was assigned to Maryville Academy in Des Plaines.

Ryan did not return messages seeking comment left Sunday.

Cupich said the allegations have been reported to Illinois Department of Children and Family Services and the Cook County state’s attorney’s office. Officials with DCFS and the state’s attorney’s office did not return messages left Sunday.

The Archdiocese of Chicago, which covers Cook and Lake counties, serves around 2.2 million Catholics.

Ryan was ordained in Springfield in June 1979 and started working in Maryville six year later. He became acting executive director in 2003. He also worked in southwestern Illinois, serving at a Godfrey parish and as director for the Catholic Children’s Home in Alton, according to the Lake Zurich church’s website.