Diop rose to prominence at the 2002 FIFA World Cup in Japan/Korea, where he scored the opening goal of the tournament as minnows Senegal defeated defending champions France 1-0.
A towering presence in midfield, Diop also had spells in England with West Ham United and Birmingham City and also played for Lens in France.
Diop won 63 caps for the Taranga Lions of Senegal, scoring 11 goals and was also a member of the side that lost the 2002 Africa Cup of Nations final on penalties to Cameroon.
He won the FA Cup during his stint with Portsmouth in 2008 and his manager at the time, Harry Redknapp, was one of the first people to pay tribute to Diop.
"He was such a wonderful character," Redknapp told BBC Radio 5 Live. "He was fantastic for me, a great character, always happy and always had a smile on his face. He was a giant of a man.
"He had no aggression in him. He looked aggressive on the pitch because he was so big, but there was nothing nasty about him.
"My thoughts are with all his family."
Senegal president Macky Sall paid tribute on Twitter, saying: "The death of Pape Bouba Diop is a great loss for Senegal.
"I pay tribute to a good footballer, respected by all for his courtesy and his talent, proudly reminding us of the Lions saga in 2002. I offer my heartfelt condolences to his family and to the football world."
