She has told reporters the night before her husband died, she cooked a traditional Indian meal for him and their family, including Khan's daughter and Ansari's father. Not feeling well, Khan retired early, Ansari told the Chicago Sun-Times, falling asleep in a chair, waking up in agony, then collapsing in the middle of the night. She said she called 911.
"It has been an incredibly hard time," she told ABC News last week. "We went from being the happiest the day we got the check. It was the best sleep I've had. And then the next day, everything was gone.
"I am cooperating with the investigation," Ansari told ABC News. "I want the truth to come out."
Ansari has not been named a suspect, but her attorney, Steven Kozicki, said investigators did question her for more than four hours last year.
"Absolutely, positively, you know, she had nothing to do with her husband's death," Kozicki said.
Despite the legal battle over the estate, Minhaj Khan said the family "can't really point fingers or we can't really speculate until a further investigation is done."
"When they are exhuming his body, I really hope the truth does come out, and our family finds some peace and we get to the bottom of this," he said. "Because everybody has to go one day, but the way that he died was not the way to go."
ABC News' Michael James contributed to this report.