The inquiry comes just weeks after a Singapore syndicate was named as a key part of a global match-fixing ring.

BBC: Singapore regulator investigates football officials

Williams turned again to his old trainer Jim McDonnell, and returned to the ring with a low-key first round stoppage of Ratko Draskovic in April.

BBC: Danny Williams - champion of the world?

Rajaratnam led what has been described as the largest insider trading ring ever, building a network of high-ranking experts in key technology and consulting firms.

FORBES: Rajaratnam's Sentence Brings Closure to the Galleon Scandal