The Fifa presidential election will take place on Friday as planned despite the arrest of seven Fifa officials on charges they received millions of US dollars in bribes.
Among those arrested is Fifa vice-president Jeffrey Webb.
A separate criminal investigation into how the 2018 and 2022 World Cups were allocated has also begun.
But Fifa has already ruled out a revote, insisting Russia and Qatar will remain the respective hosts.
Sepp Blatter faces Prince Ali bin al-Hussein in Friday's election as he seeks a fifth term as Fifa president.
Prince Ali described Wednesday's developments as "a sad day for football" but declined to comment further.
The seven Fifa officials were arrested after the US Department of Justice issued a 47-count indictment charging 14 defendants with racketeering, wire fraud and money laundering conspiracies in a 24-year scheme.
"The indictment alleges corruption that is rampant, systemic and deep-rooted," said New York attorney general Loretta Lynch.
"It spans at least two generations of soccer officials who, as alleged, have abused their positions of trust to acquire millions of dollars in bribes and kickbacks."
The charges allege:
- Nine current or former Fifa officials, including Webb and former Fifa vice-president Jack Warner, charged with corruption
- Four individual and two corporate defendants, including former Concacaf general secretary Chuck Blazer and Warner's sons Daryan and Daryll, plead guilty
- Alleged scheme "fostered a culture of corruption and greed that created uneven playing field"
- "Undisclosed and illegal payments, kickbacks and bribes became a way of doing business at Fifa"
- Majority of scheme involved corruption over media and marketing rights to matches and tournaments
Those arrested in a dawn raid at the prestigious Baur au Lac hotel in Zurich were Webb, Eduardo Li, Julio Rocha, Costas Takkas, Eugenio Figueredo, Rafael Esquivel and Jose Maria Marin.
In a separate move, just hours after the earlier arrests, Swiss authorities also opened criminal proceedings over the awarding of the hosting rights to the 2018 and 2022 World Cups.
The case involves bribes of "more than $100m" linked to commercial deals dating back to the 1990s for football tournaments in the US and Latin America, the Swiss Federal Office of Justice said in a statement.
It added that electronic data had been seized from Fifa's headquarters in Zurich as part of a probe into "criminal mismanagement" and "money laundering".
Swiss police said they intended to question 10 Fifa executive committee members who took part in the voting process in December 2010.
Russia and Qatar will host the 2018 and 2022 Word Cups respectively.
Fifa, world football's governing body, has been dogged by allegations of corruption and wrongdoing in recent years.
The latest developments are another major blow, although Fifa communications director Walter De Gregorio insisted the organisation was continuing to reform.
"This is good for Fifa," he told a news conference following news of the arrests. "It hurts, it is not easy, but it confirms we are on the right track."
Fifa later issued a statement welcoming "actions that can help contribute to rooting out any wrongdoing in football".
Dozens of soccer officials are in Switzerland for the Fifa congress and presidential election, where Blatter is widely expected to win re-election.
Subject: Fifa presidential election to go ahead despite corruption arrests 
