ZURICH: An important witness has offered information to help criminal proceedings against long-time president of the world soccer body FIFA, Sepp Blatter, the Swiss attorney general's office said on Thursday.

Spokesman Andre Marty said in an interview with TV programme "Morgenmagazin", broadcast on German channel ARD, that it should be clear by the end of 2016 to mid-2017 whether there was evidence to bring a charge against Blatter whose presidency has ended with the worst corruption scandal in FIFA's history.

"In the name of the office of the attorney general of Switzerland I can confirm that a witness has given us interesting information that is relevant for the case and should be essential for the investigation," Marty said in an emailed statement.

In the TV interview, Marty used the term "whistleblower" to describe the witness, suggesting he might be a FIFA insider. He declined to comment on that point in the emailed statement.

Swiss prosecutors last year opened a criminal investigation of individuals on suspicion of mismanagement and money laundering related to allocation of the 2018 and 2022 World Cups to Russia and Qatar.

In September the Swiss attorney general's office also announced that it had opened a criminal investigation into FIFA president Sepp Blatter over a 2.0 million Swiss franc payment made by FIFA to European soccer boss Michel Platini.

The payment was made in 2011 for work completed in 2002 by Platini, who has been described as being between a "witness and an accused person" by Swiss attorney general Michael Lauber.

Blatter and Platini, who were subsequently banned for eight years each by FIFA's own ethics committee, have denied wrongdoing. A new president will be elected in February.

A criminal investigation is also under way in the United States where 41 individuals, including a number of leading football federation presidents and FIFA officials, and sports entities have been indicted.