Officials said the checks issued to winners May 1 bounced because an employee forgot to approve the funds to U.S. Bank before the winners attempted to cash the checks, which ranged from $847 to $2,565, WLS-TV, Chicago, reported Tuesday.
Charles Cinquegrani, the winner of the $2,565, said he was shocked when the check bounced.
"They said the check you deposited is no good. I said, 'what?!' I couldn't believe it," said Cinquegrani, who won the money from a Pick 4 ticket.
Illinois Lottery spokesman Mike Lang said officials are working to prevent future problems.
"It was a mistake, we're not happy with it. We're actually looking at possibly, maybe in our procedures, minimizing the likelihood that this can happen again," Lang said.
Lang said the lotto reissued checks to the winners and repaid them for any bounced check fees.