A humble 5-cent coin with a storied past is headed to auction and bidding expected to top $2 million a century after it was mysteriously minted.

The 1913 Liberty Head nickel is one of only five known to exist, but it's the coin's back story that adds to its cachet: It was surreptitiously and illegally cast, discovered in a car wreck that killed its owner, declared a fake, forgotten in a closet for decades and then found to be the real deal.

It all adds up to an expected sale of $2.5 million or more when it goes on the auction block this spring in suburban Chicago.

"Basically a coin with a story and a rarity will trump everything else," said Douglas Mudd, curator of the American Numismatic Association Money Museum in Colorado Springs, Colo., which has held the coin for most of the past 10 years. He expects it could fetch more than Heritage Auction's estimate, perhaps $4 million and even up to $5 million.

"A lot of this is ego," he said of collectors who could bid for it. "I have one of these and nobody else does."

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The sellers who will split the money equally are four Virginia siblings who never let the coin slip from their hands, even when it was deemed a fake.

The nickel made its debut in a most unusual way. It was struck at the Philadelphia mint in late 1912, the final year of its issue, but with the year 1913 cast on its face -- the same year the beloved Buffalo Head nickel was introduced.

Mudd said a mint worker named Samuel W. Brown is suspected of producing the coin and altering the die to add the bogus date.

The coins' existence weren't known until Brown offered them for sale at the American Numismatic Association Convention in Chicago in 1920, beyond the statute of limitations. The five remained together under various owners until the set was broken up in 1942.

A North Carolina collector, George O. Walton, purchased one of the coins in the mid-1940s for a reported $3,750. The coin was with him when he was killed in a car crash on March 9, 1962, and it was found among hundreds of coins scattered at the crash site.

One of Walton's heirs, his sister Melva Givens of Salem, Va., was given the 1913 Liberty nickel after experts declared the coin a fake because of suspicions the date had been altered. The flaw probably happened because of Brown's imprecise work casting the planchet -- the copper and nickel blank disc used to create the coin.

"For whatever reason, she ended up with the coin," her daughter, Cheryl Myers, said.

Melva Givens put the coin in an envelope and stuck it in a closet, where it stayed for the next 30 years until her death in 1992.

The coin caught the curiosity of Cheryl Myers' brother, Ryan, the executor of his mother's estate. "He'd take it out and look at it for long periods of time," she said.

Ryan Myers said a family attorney had heard of the famous 1913 Liberty nickels and asked if he could see the Walton. "He looked at it and he told me he'd give me $5,000 for it right there," he said, declining an offer he could not accept without his siblings' approval.

Finally, they brought the coin to the 2003 American Numismatic Association World's Fair of Money in Baltimore, where the four surviving 1913 Liberty nickels were being exhibited. A team of rare coin experts concluded it was the long-missing fifth coin. Each shared a small imperfection under the date.

"The sad part is my mother had it for 30 years and she didn't know it," Cheryl Myers said. "Knowing our mother, she probably would have invested it for us. She always put her children first."

Since its authentication, the Walton nickel has been on loan to the Colorado Springs museum and has been publicly exhibited nationwide.

The coin will be up for grabs April 25 at a rare coin and currency auction.

Todd Imhof, executive vice president of Heritage, said the nickel is likely to attract lofty bids that only a handful of coins have achieved at auction. A 1933 double eagle, a $20 gold coin, holds the U.S. record: $8 million.

Imhof expects the Walton nickel to generate some buzz.

"This is a trophy item that sort of transcends the hobby," he said. "It's an interesting part of American history and there are collectors who look for something like this."

Ryan Myers said he's not keen on selling the nickel.

"First of all, it had been in the family for so long," he said. "It's not like something you found in a flea market or something you just found."

Cheryl Myers said they're often asked why they held on to the coin for a decade after they learned it was authentic instead of immediately cashing it in.

"It was righting a 40-year-old wrong," she wrote in an email. By allowing the American Numismatic Museum to display it for the past decade, it was honoring Walton's wishes.

"It has been quite a ride," she said.