A man who died after winning \$1m (£620,000) in the Illinois Lottery was poisoned with cyanide, a medical examiner has ruled.
Urooj Khan, who scooped the bumper prize in the summer, was initially found to have died of natural causes but a full toxicology test, demanded by a relative, has now revealed he had ingested a deadly amount of cyanide.
A murder investigation has been launched by the Chicago Police Department, and it is likely that the lottery winner's body will be exhumed as part of the inquiry.
Cook County medical examiner Stephen Cina said such cases of cyanide poisoning were "pretty unusual".
"I've had one, maybe two cases out of 4,500 autopsies I've done," he added.
Mr Khan died on July 20, 2012, a day after the \$425,000 (£264,000) cheque from his lottery win was issued.
Instead of taking the full amount in instalments, Mr Khan opted for a lump sum of just over \$600,000 (£372,000). After taxes, the winnings amounted to about \$425,000 (£264,000).
Mr Khan's cheque was cashed on August 15. If a lottery winner dies, the money normally goes to his or her estate.
The 46-year-old, who owned a number of dry cleaners, bought the winning scratchcard at a 7-Eleven shop near his home in West Rogers Park, Chicago.
He recalled the win days later at a ceremony in which Illinois Lottery officials presented him with the cheque, explaining how he jumped up and down and repeatedly shouted: "I hit a million!"
He said he was so overjoyed he ran back into the store and tipped the sales assistant \$100 (£62).
"Winning the lottery means everything to me," Mr Khan added at the ceremony in June, which was also attended by his wife, their daughter, and several friends.
He said he would put some of his winnings into his businesses and donate some to a children's hospital.
At the time of Mr Khan's death, no signs of trauma were found and a post mortem was not carried out because they were not automatically performed by the Cook County medical examiner on those aged 45 and older unless the death was suspicious.
The cut-off age has since been raised to 50.
A basic toxicology screening for opiates, cocaine and carbon monoxide came back negative, and the death was ruled to be a result of the narrowing and hardening of coronary arteries.
But a family member, who has not been identified, came forward and asked the authorities to look into the case further.