Police opened an investigation, which Fifa says it instigated in November, weeks ago as they continue to look into possible criminal mismanagement and money laundering related to the next two editions of the tournament.
World football's governing body handed over computer data willingly at its Zurich headquarters to help with the investigation, Swiss police say.
The probing is not connected to the FBI investigation which saw a number of past and present Fifa officials indicted and arrested in raids on Fifa headquarters in May.
Police insist that Fifa's president Sepp Blatter and secretary general Jerome Valcke are not suspects in the case.
Fifa revealed earlier on Wednesday that it is suspending the bidding process for the 2026 World Cup amidst the latest investigations.