Lausanne - FIFA said on Friday that it had sent a 1 300-page internal report to Swiss authorities investigating corruption and that Bern will share the findings with US officials also probing graft in football.
Open criminal investigations in both countries targeting former football executives prevented FIFA from disclosing details of its investigation, the body said in a statement.
But a source familiar with the FIFA report told AFP it "contains a lot of emails, contracts (and) will be helpful to the authorities".
FIFA began its investigation in June 2015, one month after Swiss police acting on a US warrant raided a Zurich hotel and arrested seven football executives, triggering the largest corruption scandal in the history of the sport.
The recently-completed FIFA report is based on a review of more than 2.5 million documents, interviews with "key witnesses" and is focused on "issues of primary concern to the Swiss and US authorities", the statement said.
US prosecutors in New York have indicted 40 football and sports marketing executives over allegedly receiving tens of millions of dollars in bribes and kickbacks.
FIFA's disgraced former president Sepp Blatter - still in office when the probe was launched - is currently the target of an investigation by the Swiss attorney general into criminal mismanagement.
His one-time heir apparent, Michel Platini, is implicated in the Swiss case over receiving a $2 million payment authorised by Blatter in 2011 that was allegedly "disloyal" to FIFA.
Both Blatter and Platini have been banned from football for six years.
FIFA President Gianni Infantino, who succeeded Blatter last year, said FIFA conducted the investigation to "hold wrongdoers within football accountable".
With this evidence, prosecutors "will continue to pursue those who enriched themselves and abused their positions of trust in football", Infantino said in a statement.