A Chicago man died from cyanide poisoning one day after receiving his lottery winnings and police are investigating the death as a homicide.

In June, Urooj Khan, 46, won $1 million in an instant lottery game, which he chose to get in a lump sum. On July 19, a cheque was issued to Khan for $424,449.60 - his winnings after taxes, The Chicago Tribune reported. On July 20, Khan died.

The coroner initially determined Khan died of natural causes, but family members expressed concerns and the coroner investigated further, The Tribune reported.
Autopsy results came back in December showing fatal levels of cyanide in Khan's body, the paper said, and his death how now been deemed a murder.

Police are now investigating Khan's death and his body may be exhumed for further testing.
Sources told the Tribune Khan's recent cash windfall hasn't been ruled out as a motive for his murder.