Former FIFA executive Chuck Blazer has reportedly aided the US investigators expose corruption within the football's governing body.
According to the BBC, Blazer agreed a deal with prosecutors after pleading guilty to charges of bribery, money laundering and tax evasion.
A judge conceded to reveal the details following a request by five media groups.
As per the document, Blazer worked undercover from December 2011 while on the body's executive committee.
