"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."
Urooj Khan won $1 million in a scratch-off Illinois Lottery game in June, though he elected to take the lump sum payout amounting to $425,000 after taxes. He said he planned to use the money to pay off his bills and mortgage, and make a contribution to St. Jude Children's Research Center.
Minhaj Khan remembered his uncle as that sort of giving person.
"He had a successful business, he was a great father, he was a great uncle to us and we knew him since the late '80s, since he came here [to the United States]," he said. "We lived with him. My kids used to play with him too, you know? I have two little girls. He was a really big family man and everybody loved him.
"He was the life of the party," he said, "always joking around, always joking with us and the family."
ABC News' Susanna Kim contributed to this report.