The father and coach of undefeated UFC lightweight champion Khabib Nurmagomedov, Abdulmanap Nurmagomedov, has died at the age of 57.

The elder Nurmagomedov had been taken to Moscow and hospitalized in May after testing positive for the coronavirus (COVID-1) and symptoms of the illness exacerbated an existing heart condition.

The younger Nurmagomedov's manager, Ali Abdelaziz, announced his father's death earlier Friday on Twitter.

TSN's Aaron Bronsteter confirmed Nurmagomedov's death later on Friday.

A native of Dagestan, Nurmagomedov served as coach for several other fighters across multiple disciplines, including UFC lightweight Islam Makhachev.

The elder Nurmagomedov last accompanied his son to the ring for his UFC 242 title defence against Dustin Poirier last September in Abu Dhabi.