The brother of a Chicago man poisoned with cyanide shortly after winning the lottery said Monday he is the family member who asked authorities to reconsider the initial finding that his sibling had died of natural causes.

Imtiaz Kahn said he had nightmares about his brother before his death and that his suspicions about the death lead him to push coroner's officials to conduct more tests. Urooj Khan, 46, died July 20 as he was about to collect his $425,000 in Illinois State Lottery winnings.

Imtiaz Khan said Monday in a telephone interview that he began demanding more tests be conducted immediately after coroner's officials said his brother had died of natural causes.

Further tests revealed in November that Urooj Khan had been poisoned. His body was exhumed in January for more testing.

Khan's widow, Shabana Ansari, and other relatives have denied any role in his death and expressed a desire to learn the truth.

Urooj Khan had moved to the U.S. from his home in Hyderabad, India, in 1989, setting up several dry cleaning businesses and buying into some real estate investments.

Despite having foresworn gambling after making the hajj pilgrimage to Mecca in 2010, Khan bought a lottery ticket in June. He said winning the lottery meant everything to him and that he planned to use his winnings to pay off mortgages, expand his business and donate to St. Jude's Children's Research Hospital.

He was just days from receiving his winnings when he died before dawn July 20.

The night before, Khan ate dinner with his wife, daughter and father-in-law at their house. Sometime that night, Khan awoke feeling ill. He died the next morning at a hospital.

Khan died without a will, opening the door to a court battle. The businessman's widow and siblings fought for months over his estate, including the lottery check.