STATE COLLEGE, Pa. -- Joe Paterno's dispute with officials has reached a new level.

An effigy of a football official, hung with a string around its neck and a yellow flag in hand, was on the front door of the Penn State coach's home Sunday.

It was unclear when the referee doll was placed on Paterno's door or by whom. Sports information director Jeff Nelson said Sunday that Paterno would not comment.

Paterno has been frustrated with officials this season, as all three of No. 16 Penn State's losses -- to Iowa, Michigan and Ohio State -- have involved questionable calls.

Against Iowa, one official ruled a catch in overtime good, and a second official called it out of bounds. Penn State lost that game 42-35, and Paterno raced down the field and grabbed the jersey of an official to protest.

In a 27-24 overtime loss at Michigan, a disputed call denied the Nittany Lions a chance at a potential game-winning field goal.

Against Ohio State, Penn State's last drive stalled when Zack Mills' pass landed in front of receiver Bryant Johnson. Replays appeared to show Ohio State cornerback Chris Gamble holding Johnson. No flag was thrown, and Ohio State won the game 13-7.