According to the Swiss attorney general’s spokesman, André Marty, their investigation is progressing well and formal charges could be announced by the end of this year.

He claims the information will speed up the probe into Blatter, who was suspended from all footballing activity for eight years in December along with UEFA chief Michel Platini over a "disloyal" payment of CHF2 million (£1.3 million/$1.9 million/€1.8 million) given to the Frenchman by the Swiss in 2011.

“A witness, a so-called whistleblower, gave us interesting information relevant to the case which brought us markedly forward in the criminal investigation,” Marty told German broadcaster ARD.

Criminal proceedings were opened against Blatter back in September following accusations of financial mismanagement within the corruption-plagued governing body.

As well as the payment to Platini, who gave up his attempt to replace the Swiss as the head of FIFA earlier this month, the investigation is focusing on Blatter, President of the organisation since 1998, signing an “unfavourable contract”.

It is claimed this relates to a rights deal between FIFA and disgraced former Confederation of North, Central American and Caribbean Association President Jack Warner, who has been banned from football for life, back in 2005.

Both Blatter and Platini are appealing their bans and have confirmed they will pursue all avenues in their bid to get their suspensions overturned.

They have consistently denied any wrongdoing.

The Investigatory Chamber of the FIFA Ethics Committee, however, are contesting the eight-year bans, claiming the sanctions given to the pair were too lenient.

They are hoping to get Blatter and Platini banned from football for life.

Despite being hit with the suspension, the Swiss remains adamant that he can only be removed from his position by FIFA’s 209 Member Associations.

It has been reported that the Swiss will still attend the upcoming Extraordinary Elective Congress in Zurich on February 26, where his tumultuous tenure in charge of world football’s governing body is due to come to an end.

His appeal is unlikely to have been heard by then but his spokesman, Thomas Renggli, claims Blatter “should be present at the cingress”.

“Only the congress, according to the statutes, can put Mr. Blatter out of his mandate,” he told the Associated Press.

Asian Football Confederation President Shaikh Salman Bin Ibrahim Al Khalifa, UEFA general secretary Gianni Infantino, Jordanian Football Association President Prince Ali Bin Al Hussein, Frenchman Jérôme Champagne and South African businessman Tokyo Sexwale are the five candidates in the election.