Grant Wahl, a leading American sports reporter who died suddenly on Dec. 10 while covering the 2022 FIFA World Cup in Qatar, suffered a fatal rupture of the aorta, the main blood vessel leading from the heart, his wife said on Wednesday.

"There was nothing nefarious about his death," said Celine Gounder, a renowned epidemiologist, dismissing speculation on social media that Wahl's death was the result of foul play or a COVID-19 vaccination.

In a message published on Wahl's Substack page, Gounder said an autopsy performed in New York, the United States, found that the 49-year-old Wahl had died from a rupture of a "slowly growing, undetected ascending aortic aneurysm.”

An aortic aneurysm is a rupture of the aorta, the major blood vessel carrying blood away from the heart.

"The chest pressure he experienced shortly before his death may have represented the initial symptoms," said Gounder. "No amount of CPR or shocks would have saved him."

"His death was unrelated to COVID[-19]," she said. "His death was unrelated to his vaccination status."

Wahl collapsed while covering the quarterfinal between Argentina and the Netherlands on Friday.

He had complained on his Substack of feeling poorly in the week before his death.

Days earlier, Wahl had a run-in with Qatar's World Cup organizers over a rainbow lesbian, gay, bisexual, transgender and queer (LGBTQ) shirt that he wore to a match. Qatar criminalizes homosexuality and Wahl said security guards told him the shirt was "political.”

Wahl, who was covering his eighth World Cup, helped build soccer's popularity in the US through his reporting for Sports Illustrated, CBS Sports and other media.