Urooj Khan Update: Autopsy sheds no new light about how Chicago lottery winner was poisoned, report says

(CBS) -- A medical examiner announced Friday that an autopsy on the exhumed body of a poisoned Chicago lottery winner shed no new light on how cyanide got into his system, CBS Chicago reports.

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Cook County medical examiner Stephen Cina said the exhumed body of 46-year-old Urooj Khan was badly decomposed and an autopsy could find no cyanide in the remaining tissue.

"No cyanide was detected in the tissues, which were heavily putrefied and decomposed," he said.

Cina said he could not determine if the cyanide was ingested with food or introduced to Khan's system in another matter. But Cina said Khan's case is still considered a homicide and insisted that the cause of death was cyanide toxicity, with coronary artery disease being a contributing factor due to a 75 percent blockage in one of Khan's arteries.

Khan died on July 20, 2012, less than a month after he won a $1 million prize on an instant lottery ticket. He died before he could collect his winnings.

Authorities exhumed Khan's body in January to gather more evidence in case charges are filed. His death was initially ruled to be the result of natural causes, but his family pushed for a closer look. Tests of blood samples from his body showed lethal levels of cyanide, reclassifying the case as a homicide.

No suspects were named in Khan's death.

Complete coverage of Urooj Khan on Crimesider