CHICAGO, United States (AP):

Urooj Khan had returned to the US from the hajj pilgrimage to Saudi Arabia inspired to lead a better life and had sworn off buying lottery tickets, except just this once.

To his astonishment, the ticket was a $1-million winner. But just as he was about to collect his money, Khan died. There were no signs of trauma and nothing suspicious, and the Cook County Medical Examiner's office said he died in July of natural causes.

Now, authorities have determined that Khan, 46, ingested a lethal dose of cyanide. The finding, spurred by a relative's pleas for an expanded screening, has triggered a homicide investigation, the Chicago Police Department said Monday.

"It's pretty unusual," said Cook County Medical Examiner Stephen Cina, commenting on the rarity of cyanide poisonings. "I've had one, maybe two cases out of 4,500 autopsies I've done."