A Hot Lotto ticket worth $16.5 million was sold at a Des Moines convenience store one month ago and no one has come forward yet to claim the big prize. Iowa Lottery CEO Terry Rich says he believes the person holding the ticket doesn’t realize it’s a winner.

“We can speculate a lot of things, but what we do know is someone out there has it and our assumption today is that they don’t realize it’s in their pocket, in a drawer or their car,” Rich said. The ticket was purchased at a Quik Trip on the northeast side of the capital city. It matched all six numbers in the Hot Lotto drawing on December 29.

“This particular ticket was a multiple draw ticket. So, as we looked at it, we were assuming they were probably waiting for all the draws to happen in case they won the big jackpot again or others and then would come in and claim the ticket,” Rich said. “That has not happened.” The last drawing on the ticket was on January 8. Rich says the lottery’s computers show the ticket also hasn’t been scanned at a lottery terminal in the state.

“We did a check of our system this morning,” Rich said. “Who ever does have the ticket has not gone to one of our retailers to check the ticket to see if it’s a validated winner.” Rich confirmed the lottery has video from the QT store of a person purchasing the ticket – but he declined to provide more details.

“We do have surveillance video of what could be the transaction. Verification will only happen once someone comes in and claims the ticket,” Rich said. The QT store is located just off Interstate 80/35, so Rich says the ticket holder could be a traveler from out of state. The $16.5 million jackpot is the largest unclaimed prize in the Iowa Lottery’s 25-year history.

Rich believes it’s the second largest unclaimed Lotto prize in U.S. history. A Powerball ticket sold in Indiana in 2002, worth $51 million, went unclaimed. Hot Lotto tickets are sold in Iowa, 13 other states and the District of Columbia. The individual holding the winning ticket has until December 29, 2011 to claim the prize.

Listen to the entire Iowa Lottery press conference here: Lottery 10:07 MP3