Williams' fishing license and personal notes he'd written about local fishing holes were among the items that were stolen from the Knotty Pine Auction Service last week, apparently during a private preview of auction items.
According to the New Hampshire Union Leader, auctioneer John Pappas explained that the items could have sold for more than $1,000 at the event and included Williams' 1970 fishing license and a fishing cap.
The items had been put up for auction by Williams' third wife, Dolores Wettach Williams.
Pappas said that only a handful of people were at the preview, held in Swanzey, N.H., on May 28, but he could not identify who the thief was. He did add, however, that if the items show up on a site such as eBay, they would be identified as such.
Lisa Winston is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.