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

Meraj Khan took exception to a statement police provided The Associated Press on Friday that said the probe into Urooj Khan’s death remains “very much an open and active investigation.”

She says the detective on the case has told relatives over the years he’s too busy to even answer their phone inquiries seeking updates.

She said Saturday that, in particular, 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.