ITV News Correspondent Paul Davies reports.
Jack Warner, the former Fifa vice president, has vowed to release an "avalanche" of secrets in an extraordinary television address in Trinidad and Tobago.
Warner - who is among 14 officials indicted on bribery charges - claimed he would prove a link between football's governing body and his nation's elections in 2010.
"I will no longer keep secrets for them who actively seek to destroy the country," the 72-year-old said in his address entitled "The gloves are off".
Warner said he had documents relating to financial dealings with Fifa as well as evidence linking the governing body with the 2010 Trinidad and Tobago government elections.
Despite claiming to fear for his life, Warner said nothing would stop him revealing everything he knows.
"Not even death will stop the avalanche that is coming," he said. "The die is cast. There can be no turning back. Let the chips fall where they fall."
Speaking about outgoing Fifa president Sepp Blatter, who resigned on Tuesday, Warner said: "Blatter knows why he fell. And if anyone else knows, I do."
Blatter has denied any wrongdoing.
The claims come after former senior Fifa official Chuck Blazer admitted that he and others took bribes when deciding on the host nations for the 2010 and 1998 World Cups.