Alex Duff works for FIFPro, the world football players union, in the Netherlands.
Previously he worked in Rio de Janeiro for the Associated Press and in Madrid for Bloomberg News.
'Football's Secret Trade', his first book, was written with Tariq Panja.
The book shows how since the 1990s a opaque secondary market has developed alongside the booming football transfer market.
The hidden world of offshore business has enriched everyone from oligarchs and tax exiles to player agents, while risking the integrity and financial health of the game.