U.S. officials say the winner of a $1 million lottery jackpot was poisoned last year before he could receive his award money.

Authorities this week determined that Urooj Khan ingested a lethal dose of cyanide. Cook County Medical Examiner Stephen Cina said a relative had asked authorities to further look into his death after initial results said he died of natural causes.

Urooj Khan, who emigrated to the U.S. from India, died July 20, a day after a check for his lottery winnings had been issued by the state of Illinois.

The proud owner of Chicago dry cleaners bought the lucky ticket at a convenience store. He shouted, “I hit a million!” and tipped the clerk $100 after he scratched off the winning ticket.