A man recently won a life-changing sum of money in a lottery drawing, only to then die less than a month later, before he'd even finished planning what he would do with his newly acquired fortune.

Brazilian cattle rancher Antonio Lopes Siqueira, 73, collapsed and died of a reported heart attack in a dentist's office on Dec. 4, just 24 days after he'd scored a multi-million jackpot win in Brazil's Mega-Sena draw on Nov. 9, according to The Sun.

Investigators are now probing Siqueira's death to determine the proximate cause and whether it was related to pre-existing health conditions, the shock of the lottery win, or potentially even murder.

Ongoing investigation into cause of death

According to the Mirror, Siqueira was the sole winner of a Mega-Sena lottery jackpot worth 201 million Brazilian Reals, or about $34 million in U.S. currency, when his six randomly selected numbers were drawn on Nov. 9.

Less than a month later, however, Siqueira was pronounced dead after collapsing from a suspected heart attack while in the waiting room of a dentist's office.

An autopsy suggested that he'd suffered a massive cardiorespiratory arrest, but that was not confirmed as the cause of death, as other pre-existing conditions like diabetes and high blood pressure may have been contributing factors, with

A spokesperson for Brazil's forensic medical office said in a statement, "Additional exams will be necessary for this conclusion."

The news report noted that the ongoing investigation is also seeking to determine whether Siqueira's shock at winning the large sum may have contributed to his death, not to mention the possibility that he may have been the victim of murder.

Was receiving dental work after winning the lottery

According to the Daily Mail, Siqueira's friends said the lucky lotto winner was still trying to figure out what he spend his newly acquired fortune on, though he had already decided to buy a new home and obtain some dental work.

Indeed, records show that he had already begun to receive some dental work a week before his death and was at the dentist waiting for an implant procedure when he collapsed and died from the suspected heart attack.

Investigators have reportedly interviewed the dentist and other witnesses, and the local police chief said in a statement, "The investigation is ongoing and what we can say is that, so far, there is no confirmation that the death has any connection with the Mega-Sena prize."

"It's a shame he can't enjoy it"

The Daily Mail also cited local media reports which claimed that Siqueira was a regular player of the lottery who bought his tickets from the same shop and often joked about how he'd eventually win the jackpot.

"It's very sad, everyone dreams of earning that kind of money," Yesser Dahrouge, the owner of the shop that sold the winning ticket to Siqueira, said. "It's a shame he can't enjoy it."

Per The Sun, Siqueira overcame 50 million to one odds against his six randomly selected numbers being drawn to score a sum that ranks in the top 10 largest jackpots in the Brazilian lottery's history.