Former top football official Chuck Blazer, whose evidence to US investigators was key in the FIFA corruption scandal, has died aged 72, his lawyers said on Wednesday.
Blazer, whose admissions of corruption ultimately led to the downfall of Sepp Blatter, long-time FIFA president, had been battling cancer up to his death.
Blazer, a former FIFA executive committee member, was himself banned for life from all football activities in 2015 for accepting bribes in conjunction with bids to host previous football World Cup contests.
"We are truly saddened by the passing of our client and friend, Chuck Blazer," his lawyers said in a statement to AFP new agency.
"His misconduct, for which he accepted full responsibility, should not obscure Chuck's positive impact on international soccer," the statement added.
The former vice president of US Soccer pleaded guilty in 2013 to charges of racketeering, wire fraud, money laundering and tax evasion as part of a web of corruption that spanned several decades.
It later emerged he had in fact cut a deal to work with investigators for years, taking recording devices into meetings to help build a case against corrupt officials across the globe.
"In his positions as a football official, he was a key player in schemes involving the offer, acceptance, payment and receipt of undisclosed and illegal payments, bribes and kickbacks as well as other moneymaking schemes," FIFA said as it announced his life ban in 2015.