Swiss authorities on Wednesday opened criminal proceedings against individuals on suspicion of mismanagement and money laundering related to the award of rights to host the 2018 and 2022 FIFA soccer World Cups in Russia and Qatar.
Switzerland's Office of the Attorney General (OAG) also said in a statement it had seized data and documents stored in computer systems at FIFA.
The OAG said the criminal proceedings, which were opened on March 10, are separate to a U.S. criminal investigation into the allocation of media, marketing and sponsorship rights for soccer tournaments.
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 OAG suspects that irregularities occurred in the allocation of the FIFA World Cups of 2018 and 2022, which were awarded to Russia and Qatar respectively.
It said the offences were suspected to have taken place at least partly in Switzerland, where FIFA has its headquarters.
Subsequent to the seizure of files, the OAG and Swiss police will question 10 people who took part in voting on the hosting rights for the 2018 and 2022 World Cups as members of the Executive Committee in 2010.
A spokeswoman for FIFA declined to comment.