Casino officials know how the big winner was dressed and when he played the slots. The problem is, they have no idea who walked away from the $38,000 jackpot.

Casino videotapes can't identify the man who hit it big on June 12. The way the man's head is positioned and the fact that he wore a hat has obscured the winner's face.That hasn't stopped dozens of wannabe winners from calling in to claim they are the mystery man who won the casino's largest unclaimed jackpot.

"Everybody in the world is called saying `That's me,' " said Sheila Morago, marketing director at the Gila River Casino. "They're coming in all hours of the day."

Why the man failed to claim the jackpot is itself a mystery.

"The bells and whistles went off," Morago said Monday.