04/10/2013 01:50 pm ET Updated Apr 10, 2013

Bill Mastro Honus Wagner Altered: Dealer Cops To Doctoring Most Valuable Baseball Card Ever Sold

A Chicago-area sports memorabilia dealer has copped to doctoring the most valuable baseball card ever sold.

Just days after a different copy of the prized baseball card sold for $2.1 million at auction, the Sun-Times reports the so-called “King of Memorabilia” Bill Mastro admitted to a federal judge Tuesday he altered the ultra-rare $2.8 million 1909 Honus Wagner cigarette card.

Mastro, of the wealthy Palos Park suburb 30 minutes southwest of Chicago, made his plea in order to secure a deal for 30 months in jail, the New York Daily News reports. U.S. District Court Judge Ronald A. Guzman, however, rejected the agreement between federal prosecutors and the crooked auctions dealer so that he could be free to hand down whatever sentence he sees fit.

New York attorney Jeffrey Lichtman, who represents collectors who say there were victims of Mastro's scams, called the proposed 30-month prison sentence a "slap in the face," the Daily News reports.

The Sun-Times revealed a long trail of scams allegedly perpetrated by Mastro during his time at the top of the collectibles business when he headed Mastro Auctions. Mastro is accused of "using shill bidders to drive up the prices of sports memorabilia," selling a phony lock of Elvis' hair and passing off a fake 1869 Cincinnati Reds Stockings trophy as legit.

Before coming clean, Maestro had been accused of trimming the card's edges decades ago to improve the condition and "uncover added value." The New York Post reports the copy in question was once famously owned by hockey great Wayne Gretzky.

Mastro, who appeared in court Tuesday with a Catholic priest and his brother, former New York deputy mayor Randy Mastro, faces one count of fraud. Bloomberg reports that, if convicted, Mastro could face a potential 20-year sentence.