Mino Raiola has passed away aged 54, his family have confirmed.
In a statement posted on Twitter, it was announced the Italian had lost his health battle.
It read: "In infinite sorrow we share the passing of the 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 out players.
"As usual, Mino made us proud and never realized 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. Mino's mission of making football a batter place for players will continue with the same passion.
"We thank everybody fo the huge amount of support received during these difficult times and ask for respect and privacy of family and friends in this moment of grief.
"The Raiola Family."
The agent was known for looking after Manchester United's Paul Pogba, Borussia Dortmund star Erling Haaland and the legendary Zlatan Ibrahimovic, currently with AC Milan.