( CNN ) -- The body of a million-dollar lottery winner will be exhumed for additional testing after toxicology results revealed the Illinois man died of cyanide poisoning , a judge ruled Friday . Urooj Khan won the prize in June on a scratch-off ticket . The next month , he was dead . Investigators initially ruled Khan 's cause of death natural . But after being prompted by a relative , the Cook County medical examiner 's office revisited the case and found a lethal amount of cyanide in Khan 's system . `` That ... led us to issue an amended death certificate that ( established ) cyanide toxicity as the cause of death , and the manner of death as homicide , '' Chief Medical Examiner Dr. Steve Cina said Monday . Authorities are hoping to use the exhumation to determine how the cyanide entered Khan 's system . The exhumation is expected to occur Thursday , CNN affiliate WGN reported . No arrests have been made in the case . `` We are investigating it as a murder , and we 're working closely with the medical examiner 's office , '' Chicago police spokeswoman Melissa Stratton said Monday . Related : The problems with winning the lottery . Khan , 46 , planned to use his winnings to pay his mortgage and bills , make a donation to St. Jude Children 's Research Hospital and invest more in his dry cleaning businesses . The check , which amounted after taxes to about $ 425,000 , was issued July 19 , according to CNN affiliate WGN , but Khan never got to spend it . The next night , Khan came home , ate dinner and went to bed , according to an internal police department document obtained by the Chicago Tribune . His family later heard him screaming and took him to a local hospital , where he was later pronounced dead , the paper reported , citing the document . Chicago police have n't offered details , including a possible motive , about what they call an `` ongoing investigation . '' Talking briefly with CNN affiliate WBBM and the Tribune , Khan 's widow described her husband as kind and exemplary . Jimmy Goreel , who runs the 7-Eleven where the winning lottery ticket was sold , offered similarly glowing comments about Khan . `` I would never think that anybody ... would hurt him , '' Goreel told WGN . `` ( He was a ) nice person , very hopeful and gentle ( and ) very hard-working . '' Related : Woman pleads not guilty in death of lottery winner . CNN 's Greg Botelho and Chandler Friedman contributed to this report .
Investigator want to know how cyanide entered Urooj Khan 's system . He died a day after receiving winnings from $ 1 million scratch-off ticket in Illinois . Cause of death has been ruled a homicide . No arrests made .