Authorities plan to exhume the body of a Chicago businessman Friday in hopes of learning exactly how he ingested a lethal dose of cyanide.

Urooj Khan died in July as he was about to collect $425,000 in lottery winnings. His death was initially ruled a result of natural causes, but a relative pressed for a deeper look. Full toxicology results revealed in November that Khan was poisoned. His death was reclassified a homicide.

No suspects have been identified.

The Cook County Medical Examiner's Office hopes an autopsy, expected to be finished by Friday afternoon, will produce more evidence in the event the case goes to trial.

Spokeswoman Mary Paleologos says tests on the 46-year-old Khan's organs also may determine whether the poison was swallowed, inhaled or injected.

Last week, facing dozens of reporters crowded around her outside court after a judge signed off on the request, Khan's sister said the thought of her brother's body being unearthed and reexamined was disturbing — but essential.

"It's very hard," a tearful Marez Khan said. "I wanted my brother to rest in peace, but we have to have justice served." She added about the exhumation, "It has to be done."

Khan's July 20 death was initially ruled a result of natural causes. But a relative asked authorities to look deeper, triggering more exams that led to the conclusion in November that the businessman was intentionally poisoned.

A comprehensive autopsy initially wasn't performed because there were no outward signs of physical trauma and it was thought he died of cardiac arrests, the state's attorney's motion said.

It wasn't immediately clear when the exhumation will happen. The motion said the body wasn't embalmed, which would preserve the body longer, and so the exhumation needed to happen soon before further decomposition.

Police have released few details about the investigation; they have not announced any suspects or a possible motive or said which relative asked for the more thorough inquiry.

The man's wife, Shabana Ansari, has said she can't believe her husband had any enemies and that she was not involved in his death.

One of Ansari's lawyers said before Friday's hearing that she doesn't oppose the exhumation. But Al-Haroon Husain said Ansari wants to ensure Islamic religious practices are adhered to, though he didn't elaborate.

Al-Haroon Husain said he would also ask authorities to carefully document the exhumation and autopsy, including by taking photographs, to ensure the procedures are carried out properly.