Six high-ranking soccer officials, including two vice-presidents of world governing-body Fifa, were arrested by Swiss police on Wednesday and detained pending extradition to the United States.
The arrests were made by plain-clothed police shortly after dawn at a plush Zurich hotel where Fifa officials are staying ahead of this week's Fifa presidential election.
The Swiss Federal Office of Justice (FOJ) did not identify which officials were arrested but confirmed that Fifa president Sepp Blatter was not among them.
The New York Times and the BBC both reported that Jeffrey Webb and Eugenio Figueredo, both Fifa vice-presidents, were among the six detained.
The FOJ said in a statement that the officials were suspected by U.S. investigators of having received or paid bribes totaling millions of dollars.
"The US Attorney's Office for the Eastern District of New York is investigating these individuals on suspicion of the acceptance of bribes and kickbacks between the early 1990s and the present day," the statement said.
"The bribery suspects -- representatives of sports media and sports promotion firms -- are alleged to have been involved in schemes to make payments to the soccer functionaries -- delegates of Fifa and other functionaries of Fifa sub-organizations -- totaling more than US$100 million."
More than 10 officials were expected to be indicted but not all were in Zurich. The New York Times said Jack Warner, Eduardo Li, Julio Rocha, Costas Takkas, Rafael Esquivel, José Maria Marin and Nicolas Leoz were also indicted.
Fifa did not make any immediate comment following the arrests but are due to hold a news conference at 0900 GMT on Wednesday.
Most of the officials are in Switzerland for the Fifa Congress, where Blatter faces a challenge from Jordan's Prince Ali Bin Al Hussein in a presidential election on Friday when the Swiss administrator will attempt to secure a fifth term at the helm.
Prince Ali, who has promised to clean up Fifa if elected to the top job, released a brief statement.
"Today is a sad day for football," he said.
"Clearly this is a developing story, the details of which are still emerging. It would not be appropriate to comment further at this time."
The New York Times said more than a dozen Swiss law enforcement officials arrived at Zurich's Baur au Lac hotel early on Wednesday, took keys from the registration desk and headed up to the rooms.
CONCACAF FOCUS
One Fifa official was led by the authorities from his room to a side-door exit of the hotel, the Times said, adding that officials from the body's powerful executive committee were being targeted.
"We're struck by just how long this went on for and how it touched nearly every part of what Fifa did," the paper quoted an unnamed law enforcement official as saying.
"It just seemed to permeate every element of the federation and was just their way of doing business. It seems like this corruption was institutionalized."
The Times said much of the enquiry was focused on the Concacaf region, which governs soccer in the North America, Central America and the Caribbean.
The confederation's former boss Warner was regularly dogged by accusations of corruption before he resigned in 2011, putting an end to investigations of the Trinidadian.
Prosecutors expected to announce the case at a news conference at the Brooklyn U.S. attorney's office, which is leading the investigation on Wednesday, the Wall Street Journal said in a separate report.
U.S. Attorney General Loretta Lynch, Federal Bureau of Investigation Director James Comey and Internal Revenue Service criminal chief Richard Weber were expected to appear in Brooklyn to announce the case, the WSJ said.
The reports offer a fresh blow to the credibility of Fifa, which has suffered repeated accusations of wrongdoing over the bidding process for the 2018 and 2022 World Cups, which were awarded to Qatar and Russia respectively.
Fifa appointed an independent investigator to look into the allegations and though a summary of his report found some wrongdoing on the part of the Qatari and Russian bid committees, Fifa's ethics judge concluded it was not enough to question the entire process.
The investigator, former attorney Michael Garcia, subsequently resigned from his role in December after criticising the handling of his report.
Damian Collins, the British MP who founded the reform group New Fifa Now, said the news was hugely significant for Fifa and could have a massive impact on the governing body.
"The chickens are finally coming home to roost and this sounds like a hugely significant development for Fifa," he told Reuters by telephone.
"It proves that Sepp Blatter's promises over the last few years to look into corruption at Fifa have not materialised and because he has totally failed to do this, it has been left to an outside law enforcement agency to do the job and take action."
