However the autopsy did not reveal any new clues in Khan's mysterious death. There was no cyanide left in the body tissue because it breaks down quickly, according to Cook County medical examiner Dr. Stephen Cina. Other tests revealed nothing new.
"The route of administration of cyanide cannot be confirmed in the autopsy," said Cina. "There was severe, about 75 percent, stenosis which is blockage of one of the major coronary arteries."
Cina says Khan's July 20 death is still considered a homicide because tests on fluids drawn from his body before he was buried revealed he was poisioned by cyanide which caused the artery blockage.
Authorities initially ruled that the Indian-born businessman died of natural causes, but his brother raised suspicions, leading to the further tests.
"Coronary artery disease is deemed a contributory condition, and the manner of death is homicide," Cina said Friday.
Authorities initially ruled that the Indian-born businessman died of natural causes, but his brother raised suspicions, leading authorities to test fluids drawn from Khan's body before he was buried.
Those tests showed he had been poisoned, and Khan's body was exhumed in January so that authorities could perform the autopsy and gather more evidence in case prosecutors decide to file charges.
The Associated Press contributed to this report.