Chuck Blazer is among four men linked to FIFA that have pleaded guilty to corruption charges.
Seven arrests were made in Zurich on Wednesday morning by US authorities over alleged racketeering, money laundering and wire fraud.
A separate corruption investigation has been opened by Swiss prosecutors into the allocation of the 2018 and 2022 World Cups, which are due to be held in Russia and Qatar respectively. A total of 14 people have been indicted.
It is understood that over $150m (£97m) was accepted in bribes from 1991 onwards.
Former FIFA official Blazer, Daryan Warner, Daryll Warner and Jose Hawilla have now all pleaded guilty to the charges brought forward by the US authorities.
Daryan Warner and Daryll Warner are the sons of former FIFA vice-president Jack Warner, who has also been indicted. However, the 57-year-old has pleaded his innocence.
