Mino Raiola died at the age of 54, his family revealed in a statement.
Raiola, one of the world's most renowned agents, represented some of the game's greatest names and helped revolutionize the way football transactions are performed.
On Thursday, news of his severe critical illness leaked, and a statement posted on his official Twitter account – on behalf of his family – confirmed his death.
"In infinite sorrow, we share the passing of most caring and amazing football agent that ever was.
"Mino fought until the end with the same strength he put on negotiation tables to defend our players. As usual, Mino made us proud and he never realised it.
"Mino touched so many lives through his work and wrote a new chapter in the history of modern football. His presence will forever be missed."
May he Rest in Peace.