Urooj Khan, 46, won $1 million off a scratch lottery ticket he bought at a 7-11 in Chicago last June, but just one day after receiving his check, he died. Now, his death has been ruled a homicide, as toxicology reports showed deadly cyanide in his system. NBC's Andrea Canning reports.

The wheel of fortune spun fast for Urooj Khan.

The Indian immigrant and Chicago-area dry cleaning store owner struck it big with a $1 million lottery win in June. He died a month later, succumbing to cyanide poisoning in what police are now investigating as a homicide.

The death was a dark end to the family man’s otherwise hopeful tale.

Khan came to Chicago in the 1980s and found work in a local dry cleaning business. After years of working for others, he opened Style Dry Cleaners in the Rogers Park area of Chicago in 2004. Over time, Khan became proprietor of three dry cleaning stores of his own, according to the Chicago Tribune.

He also owned five condominiums, which he rented out, the paper reported.

In a June 26 press release from the Illinois Lottery, a giddy Khan described his reaction after buying his golden ticket at a 7-Eleven in Rogers Park. “I scratched the ticket, then I kept on saying, ‘I hit a million!’ over and over again,” an effusive Khan said of his sudden riches. “I jumped two feet in the air, then ran back into the store and tipped the clerk $100.”

Khan stood to bank $424,449.60 from the win after taxes on his lump sum payout of over $600,000. He would give some of the money to St. Jude Children’s Research hospital, he said, and invest another share in his dry cleaning business. The lucky entrepreneur gripped an oversized check at the summer lottery ceremony where he was joined by his wife, Shabana Ansari, 32, and their daughter Jasmeen, along with several friends.

“Winning the lottery means everything to me,” Khan gushed in June.

$1 million lottery winner fatally poisoned by cyanide

But he never got to enjoy the windfall, dying suddenly on July 20, just one day after the check with his winnings was issued by the Illinois Comptroller’s Office.

Cook County Medical Examiner Stephen Cina performed a limited exam on the 46-year-old and found no signs of trauma. Cina’s office concluded that he had died of natural causes. Six months later, in a sudden turn of events, officials said on Monday that they were looking into Khan’s case again after further toxicology reports determined that his system held lethal amounts of cyanide.

Those tests were run at the urging of an unnamed family member.

Khan’s wife described him as a “kind and good-hearted person” to NBCChicago.com. Khan ate dinner at home with his family on the night he died, the Tribune reported, citing an internal police document. He went to bed. After he awoke screaming in the night, he was taken to St. Francis Hospital, where he was pronounced dead.

Khan was a “workaholic,” his wife of 12 years told the paper. “He made clients happy by doing his job. He could not be everywhere, but he had to be everywhere.”

Khan’s purchase of the winning ticket came in a moment of weakness, convenience store clerk Ashur Oshana told The Associated Press. The doomed man had sworn off gambling in 2010 after going on the hajj, the pilgrimage all faithful Muslims are obligated to make once in their lives. He yielded to temptation one last time, and laid down $60 for a pair of scratch-offs.

Lottery winner's death investigated as a homicide

“Right away he grabbed my hand,” Oshana said of Khan’s emotional win. “He kissed my hand and kissed my head and gave me $100. He was really happy.”

Jimmy Goreel owns the convenience store where Khan bought his winning ticket. He said Khan had been kind to him after an earlier, smaller win.

“I sold him a winning ticket for $5,000,” Goreel told NBCChicago.com. “He was so generous he reached for a hundred dollars, and he threw it on the counter for me.”

“He was a family man who worked hard for his family,” Goreel said. “I just can’t see it happening. If that’s true, it’s sad.”

Khan was buried at Chicago’s Rosehill Cemetery. Cina said exhuming his body may be the next step in investigating the death.

More content from NBCNews.com:

Follow US news from NBCNews.com on Twitter and Facebook