Dmitriy Stuzhuk caught the disease while traveling to Turkey and was taken to hospital upon his return to his native Ukraine, after testing positive.
The social media star, who promoted a healthy lifestyle, was discharged from hospital after eight days, but the virus led to heart complications.
After being taken back to hospital, his ex-wife Sofia, 25, said he was in “serious condition” and “unconscious”.
She told her supporters he was “having trouble with his cardiovascular system … his heart is not doing it.”
“His condition is extremely serious. Nobody can do anything about it.
“I did all I could to ensure that the father of my three children lived. But nothing is up to me now. ”
She later announced his death, adding, “Only warm memories remain, three beautiful children and a precious experience. ”
Previously, Mr Stuzhuk posted on social media from his hospital bed, claiming that he woke up in Turkey with a swollen neck and was having trouble breathing.
He told his 1.1 million subscribers, “I want to share how I got sick and strongly warn everyone.
“I was one of those who thought that Covid didn’t exist… until I got sick.
“COVID-19 IS NOT A SHORT-LIFE ILLNESS! And it is heavy. ”
Dmitriy and Sofia Stuzhuk separated six months ago, but they have had three children, the youngest being only nine months old.