Former FIFA executive committee member Chuck Blazer agreed to act undercover for U.S. prosecutors and has been cooperating since at least 2011 in the government's investigation of corruption in world football's governing body.

Blazer's 19-page cooperation agreement from Nov. 25, 2013, was unsealed on Monday after a federal judge agreed to a request by five media organisations and rejected an objection by federal prosecutors.

Blazer agreed "to participate in undercover activities pursuant to the specific instructions of law enforcement agents or this office" and "not to reveal his cooperation or any information derived therefrom to any third party without prior consent," according to the agreement between Blazer and the U.S. Attorney's Office in Brooklyn, New York. Blazer also agreed not to contest any ban imposed on him by FIFA or any other football governing body.

As part of the deal, Blazer agreed he had unreported income over $11 million for 2005-10 and said he would sign over title of his FIFA pension if needed to satisfy payments owed the U.S. government. He already has agreed to penalties and a fine totaling nearly $2.5 million and to pay more in the future.

In exchange for Blazer's cooperation and guilty pleas to 10 counts, the government agreed not to recommend a specific sentence for his crimes and also accepted that a reduction of up to three levels be warranted under sentencing guidelines if he "clearly demonstrates acceptance of responsibility."

An American who was football's former No. 2 official in North and Central America and the Caribbean, Blazer pleaded guilty in November 2013 to one count each of racketeering conspiracy, wire fraud conspiracy, money laundering conspiracy and willful failure to file a Report of Foreign Bank and Financial Accounts, and to six counts of tax evasion. Charges involved facilitation of bribes in connection with the selection of the 1998 and 2010 World Cup hosts, and bribes and kickbacks in conjunction with the sale of broadcast and other rights to the CONCACAF Gold Cup from 1996-2003.

American Chuck Blazer was working for U.S. law enforcement since at least 2011. FIFA/FIFA via Getty Images

His cooperation was first reported by the New York Daily News last autumn. His pleas remained secret until they were unsealed last month on the same day 14 football officials and marketing executives were indicted on corruption charges, including seven men arrested in Zurich ahead of the FIFA Congress, pending extradition to the U.S.

Just after he was elected to a fifth term as FIFA president later that week, Sepp Blatter announced his intention to resign when a successor is chosen. A law enforcement official, speaking on condition of anonymity, has said that the 79-year-old Blatter is a target of the investigation, the Associated Press has reported.

The maximum sentence to the 10 counts Blazer pleaded guilty to totals 100 years, but he is likely to serve far less time. For example, a three-level reduction to a racketeering charge could reduce the guideline sentence from 30-37 months to 21-27 months. And in many instances, judges order sentences to be served concurrently rather than consecutively.

U.S. District Judge Raymond J. Dearie also unsealed details of his order last Thursday ordering the plea agreement to be opened.