Lottery winner Urooj Khan died after ingesting cyanide (Illinois Lottery)
Lottery winner Urooj Khan died after ingesting cyanide (Illinois Lottery)

Police in Chicago have launched a murder investigation after a post-mortem revealed that a lottery winner was poisoned before he was able to collect his jackpot.

Urooj Khan, 46, died after winning $1m on a scratchcard in June but was found dead the day after the winning cheque was posted to him.

The original cause of death was given as natural causes but a full toxicology test, demanded by a relative, revealed the 46-year-old died as a result of ingesting a lethal dose of cyanide.

Chicago police confirmed they were treating Khan's death as homicide.

Cook County medical examiner Stephen Cina described Khan's death as "pretty unusual". "I've had one, maybe two cases [of cyanide poisoning] out of 4,500 autopsies I've done," he added.

There were no signs on the body of trauma or struggle so authorities originally ruled there was no need for an autopsy.

Khan won $1m on the scratchcard but chose to take his winnings in a lump sum of $600,000 rather than in instalments.

The cheque was mailed to him on 19 July, the day before he was found dead, but it was cashed on 15 August.

If a lottery winner dies, the money typically goes to his or her estate.

During a ceremony on 26 June where he was presented with his mock cheque, Khan told the crowd: "Winning the lottery means everything to me."

He said he planned to donate some of his winnings to a children's hospital and also to fund his dry cleaning business.

Deborah Blum, an expert on poisons, said the use of cyanide in killings had become rare as it was normally easy to detect and was becoming harder to obtain.

"It is that it's not one of those poisons that's tasteless," Blum said. "It has a really strong, bitter taste so you would know you had swallowed something bad if you had swallowed cyanide. But if you had a high enough dose it wouldn't matter because a lethal does will take you out in less than five minutes."

Chicago police said it was likely Khan's body would be exhumed as part of the investigation.