A corked bat used by the legendary Mickey Mantle is due to appear in Grey Flannel Auctions' June 5 Summer Games sale.
The illegal Hillerich & Bradsby Co bat holds a reserve of $5,000, with authenticators PSA/DNA grading it Game Used 7.5.
An x-ray of the bat reveals the cork inside, with PSA/DNA's John Taube commenting: "This is the first corked bat of Mantle that we have seen or heard of."
Corking is an illegal practice in baseball, used by batsmen to increase the power of their swings.
According to the New York Post, a game-used Pete Rose bat that also had a concealed cork sold for $8,000 at auction in April.
Bidding has now opening over at Steiner Sports on the 1960 contract that Mantle signed with the Yankees, which is expected to raise over $1m for Hurricane Sandy relief.