CHICAGO – 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.