Rare Nintendo cartridges found in storage could be worth millions

WAUKESHA, Wisc. (WLS) -- A box of Nintendo games found in Waukesha, Wisconsin could be worth millions.

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Inside were nearly 100 copies of a previously unknown version of Super Mario Bros. and Duck Hunt.

Experts said the cartridges were printed two years after the last known run and feature different labels, screws, manuals and motherboards.

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The seller claimed Nintendo sent the games to a metal recovery service to be melted down for gold, but they were never destroyed.

Some are in perfect condition, earning the first 10 grades from the Professional Sports Authenticator for a Nintendo Entertainment System game.

Three cartridges are headed to auction this month and could fetch millions.