Former high-ranking Fifa officials Sepp Blatter, Jerome Valcke and Markus Kattner awarded themselves pay rises and bonuses worth $80m (£55m) over five years, say Fifa lawyers.
Football's governing body revealed the contracts of ex-president Blatter, fired ex-secretary general Valcke and sacked former finance director Kattner one day after a Swiss police raid.
Fifa's lawyers said there was evidence that the trio made "a coordinated effort" to "enrich themselves" between 2011 and 2015.
Documents and electronic data were seized from Kattner's old office during Thursday's operation, which relates to investigations into Blatter and Valcke, according to sources close to Fifa's internal investigation.
Suspected of criminal mismanagement of Fifa money, Blatter and Valcke were banned for six and 12 years respectively by the governing body's ethics committee in February. Both deny wrongdoing.
A statement for the Office of the Attorney General of Switzerland (OAG), which carried out the investigations, read: "Documents and electronic data were seized and will now be examined to determine their relevance to the ongoing proceedings."
Fifa said the evidence uncovered by its own internal investigation would be shared with the Swiss Attorney General's office and the US Department of Justice.
Richard Cullen, Blatter's lawyer, said: "We look forward to showing Fifa that Mr Blatter's compensation payments were proper, fair and in line with the heads of major professional sports leagues around the world."
Meanwhile, Blatter's long-time public relations advisor Klaus Stoehlker told BBC Sport he would be ending their professional relationship, adding: "The Fifa volcano is exploding now."
Fifa has been in turmoil since May 2015, when a US investigation exposed widespread corruption at the top of the organisation.
Analysis
"Fifa has "victim status" right now from the US Department of Justice and the Swiss authorities. It acknowledges that the institution itself is not at fault for the corrupt acts of its senior members in recent times.
"But that could easily change and it's why Fifa's own legal team have been digging through millions of documents to uncover any previously unknown historic wrongdoing.
"Over the past few days they say they uncovered information which revealed the secret deals that allowed Blatter, Valcke and Kattner to gorge on huge multi-million dollar bonuses.
"Some of the provisions in the contracts could breach Swiss law.
"Now they've gone public with the information in an attempt to demonstrate to the legal authorities and fans they are serious about long term reform and regaining trust."