The crown jewels of one of America’s most notorious mobsters are up for auction after being seized following his latest arrest.

The diamond-encrusted baubles belong to Salvatore “Sammy The Bull” Gravano, the infamous Mafia hitman whose turncoat testimony brought down the American Godfather, John Gotti.

The 24 pieces, including a mono-grammed keychain and a bulky gold “pinkie ring”, have been valued by a jeweller at $100,000 (£50,000). But the public’s fascination with the Mafia lifestyle seen on TV’s The Sopranos is expected to drive prices to double that. The final episode of The Sopranos was being shown in Britain last night.

“With The Sopranos being so dominant in the culture, people are just en-amoured with mobster memorabilia,” said Brett Higgins, of Sierra Auction in Phoenix, which is selling the jewels on Saturday for the Government.

Gravano, 62, a former “underboss” in New York’s Gambino crime family, broke his oath of silence to become the highest-ranking defector in the history of the American mob.

He confessed to 19 murders and agreed to “rat” on Gotti in 1991, putting the “Dapper Don” behind bars for the rest of his life.

After serving five years in prison himself, Gravano went into the Government’s Witness Protection Programme and was relocated to Arizona under a new name. Gotti’s gang took out a contract on him but the plot was unsuccessful and earned Gotti’s brother, Peter, a 25-year jail term.

Gravano left the Witness Protection Programme to promote a book about his mob career, called U n d e r b o s s, and soon returned to a life of crime. He was arrested in 2000 for running a drug ring with his then wife and two children. As he was sent to prison for 19 years, Gravano told the court: “In my history of crime, this is a minor thing.”

The proceeds of Gravano’s jewellery will go into a government fund used to finance future racketeering investigations. The single most valuable piece is a gold man’s ring set with a single 2.5 carat diamond, which would be worth about $15,000 if it had not been owned by “Sammy the Bull”. Several other rings are also on sale, including some of the characteristic “pinkie rings” that mobsters wear on their little fingers.

“His hands were not a very large size,” Mr Higgins said.

“There are a couple that I would suspect to be pinkie rings based on their size.” Bidding is expected to be fiercest, however, for two extravagant mono-grammed diamond keychains, one bearing the initials “SG” and the other spelling out the word “SAM”.

Another piece is a white gold women’s bracelet with the word “DEBBIE” spelt out in 42 diamonds. Debbie Gravano, the mobster’s former wife, who served a brief jail term, was contacted to see if she was interested in bidding, but said that she was not.

Donald Conrad, the prosecutor who sent Gravano back to jail, said that the mobster’s life should not be glamourised.

“There is just something romantic for people about the Mafia. I suppose it started with movies like The Godfather, great movies like that. People are interested,” he told local TV.

“The fact that this man, this former underboss, was targeting young men in our community to make them part of his gang is something we felt we had to interrupt.”

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