CHICAGO (AP) — The sister of a Chicago businessman who authorities say was poisoned with cyanide after winning the lottery four years ago said Saturday that police have done nothing to solve the case.

Meraj Khan took exception to a statement police provided to The Associated Press on Friday that said the probe into Urooj Khan’s death remains “very much an open and active investigation.” She said the detective in charge of the case has told relatives over the years that he’s too busy with other things to even answer their phone inquiries seeking updates.

“Every time we called them, he hands it to somebody else who says, ‘Oh, we are looking into it,'” she said. “They haven’t done nothing, really.”

The Associated Press sought updates on the case as the medical examiner who first declared it a homicide left office this week with the matter still unresolved. His findings, which reversed an initial ruling that Khan died of natural causes, led to the exhumation of the man’s body, divided his family and drew packs of international reporters to Chicago to cover the story.

Over the course of nearly four years, police say they have interviewed three family members: Khan’s wife, daughter and father-in-law, who all had dinner with him at their home on the night he died. Detectives are continuing to talk with family members, police spokesman Anthony Guglielmi said Friday.

“It is still very much an open and active investigation,” he said, without getting into any specifics on progress, potential suspects or theories.

Meraj Khan said Saturday that it’s been years since investigators sought information from the businessman’s daughter, who witnessed events leading up to the July 2012 death after a meal prepared by her step-mother. No one has ever been charged, and the step-mother has denied killing Khan.

Guglielmi said Saturday that the police department stands by the statement that the case remains active.

Urooj Khan, who moved to the U.S. in 1989 from Hyderabad, India, ran dry-cleaning businesses with his wife in the West Rogers Park neighborhood on Chicago’s northwest Side. He won $1 million with a scratch-off lottery ticket. He opted to collect it as a $600,000 lump sum, which after taxes amounted to more than $424,000.

But the 46-year-old died July 20, 2012, one day after his lottery check was issued but before he received it. After a bitter probate battle, Khan’s estate — including the lottery check — was split between his wife and her now-estranged step-daughter.

Meraj Khan, who was granted guardianship of her brother’s daughter, continues to believe her brother’s wife and father-in-law were involved in the death, calling it an “open-and-shut case.” The wife, Shabana Ansari, is following her attorney’s instructions not to comment, but has previously denied any role in the death. So has her father.

The unresolved case has left the family feeling helpless and in anguish, Meraj Khan said.

“Honestly, a day doesn’t pass by that I don’t think about him,” she said of her brother. “Every single day. When I look at my niece, when I remember things that we did. … I feel like he’s telling me, ‘How come you’re not doing anything about it?'”