Mixed martial arts fighter Allan Nascimento has died at the age of 34, says the UFC.

According to MMA’s leading promotion, the Brazilian flyweight was found unresponsive on Monday morning after suffering an apparent heart attack in his sleep.

“Despite the efforts of the responding medical team, he was pronounced deceased at the scene,” added a UFC statement.

“Our thoughts and deepest condolences are with Allan’s family, friends, team-mates and loved ones during this incredibly difficult time.”

Nascimento had been with the UFC since 2021 and his last fight was a split-decision loss to Mitch Raposo in June.

That left Nascimento with an overall MMA record of 22 wins and seven losses, with a 4-2 record in the UFC.