TODAY | January 08, 2013
>>> police in chicago now have opened a homicide investigation into the death of a man who died just one day after he received a big lottery payout. andrea canning is here with the details on that. good morning to you.
>> good morning. at first, nothing seemed to be out of the ordinary. the death happened last july and was initially attributed to natural causes . toxicology tests show the lottery winner actually ingested a lethal dose of cyanide. now investigators have a mystery on their hands. 46-year-old aruj khan won the lottery.
>> he was so generous, like $100, throw it on the counter for me.
>> khan was planning to use the money to help his dry cleaning business, but one day after a check for nearly $425,000 was mailed to him last july, he died. at first, the cook county medical examiner's office ruled it a death by natural causes .
>> family member contacted the doctor who had done the autopsy and suggested that we might want to look a little further into the case.
>> reporter: officials now say khan's death is a murder mystery , with no suspects named so far. after comprehensive toxicology tests showed a lethal dose of cyanide was found in his system.
>> a chemical poison. basically biochemical level it asphyxiates you. a little does go a long way.
>> reporter: the night of his death, he had dinner with his wife and teenage daughter and went to bed. he was later heard screaming and taken to the hospital where he was pronounced dead. khan's widow has spoken to police but has made no additional comments. investigators will likely exhume khan's body and perform an autopsy in the days to come.