The widow of a Chicago lottery winner who authorities say was poisoned with cyanide has battled with his siblings over control of his estate, including his $425,000 prize money, court documents show. Urooj Khan, who owned several dry cleaning operations and some real estate, died suddenly on July 20, just days before he was to collect his winnings from the Illinois Lottery. With no signs of trauma, authorities initially ruled he died of natural causes, but a relative came forward with suspicions that prompted a fuller examination that led to the startling conclusion that he was intentionally poisoned. The probate court documents, reviewed by The Associated Press on Wednesday, shed no light on the circumstances of Khan's death, but they do add a layer of drama to an already baffling case. As they work to unravel the mystery, police, prosecutors and the medical examiner have revealed little, naming no suspects and declining to say if the lottery win might have presented a motive. In another development Wednesday, a lawyer for the man's widow, Shabana Ansari, said Chicago police detectives questioned her in November for more than four hours at a police station and executed a search warrant on the two-story home where she lived with Khan. Attorney Steven Kozicki said Ansari maintains she had nothing to do with the death of her 46-year-old husband and he has no indication that investigators might be looking at her as a potential suspect. "In any case where a husband dies in that manner, sure they're going to talk to the spouse," he said. That's what they've done. ... I believe that she had nothing to do with his death. She vehemently says that she had nothing to do with his death. The fact that Khan died without a will opened the door to the legal tussle over his estate, which his wife says amounts to more than $1.2 million, including the prize money, his share of the dry-cleaning businesses and real estate, as well as several vehicles and a bank account. Under Illinois law, Khan's estate would be split between his wife and 17-year-old daughter from a previous marriage. However, Khan's brother Imtiaz and sister Meraj Khan expressed concern in court filings that Khan's daughter might not get her fair share. The siblings, who live in the Chicago area, are not staking a claim to any of the money for themselves. They initially won an order from a probate judge in September to freeze the lottery check, asserting his widow tried to cash it. Meraj Khan is also seeking to become the legal guardian of the teen, who lives with Ansari. Ultimately, the probate judge granted Ansari's competing request to administer the estate but has yet to decide how to divide the assets, including the lottery payout. The assets remain held up by the court proceedings, and Ansari denies removing any of the assets. Ansari's probate attorney could not be reached for comment, and the lawyer representing Khan's siblings declined to discuss the case. Imtiaz Khan also did not return a phone message. The next status hearing is scheduled for Jan. 24. Ansari spoke to The Associated Press on Tuesday at one of the dry cleaning businesses her husband started. Ansari would not talk about the circumstances of her husband's death, saying it was too painful to recall. She said only that he fell ill shortly after they ate dinner together. She said she cannot believe her husband had enemies and she has no idea which family member asked authorities to take a deeper look into his death. Authorities have refused to identify the relative. Khan had planned to use his lottery winnings to pay off mortgages, expand his business and make a donation to St. Jude Children's Research Hospital. Ansari and Khan were both born in the southern India city of Hyderabad and immigrated to the United States as adults. Khan bought his winning instant lottery ticket in June at a convenience store near his home. It was a $1 million winner, but he opted for a lump sum. After taxes, it amounted to about $425,000, according to the Illinois Lottery.