The trial of former FIFA president Sepp Blatter and French footballing legend Michel Platini over alleged corrupt payments began in Switzerland on Wednesday with both defendants in a confident mood.

Swiss prosecutors accuse the pair, once among the game's most powerful figures, of unlawfully arranging a payment of 2 million Swiss francs ($2.08 million) in 2011. Blatter and Platini deny the charges.

Three judges at the Federal Criminal Court in Bellinzona, will hear the case in the trial which runs until June 22. A verdict is due on July 8. If convicted, Platini and Blatter face up to five years in jail.

Both have denied wrongdoing and say they had a verbal agreement over the payment, which related to consultancy work by Platini between 1998 and 2002.

Blatter, once the most powerful figure in global football, arrived at the court looking frail and accompanied by his daughter Corinne and his lawyer.

"I am absolutely confident, the sun is shining and I'm in a good mood," Blatter told journalists before the hearing.

"I know I have not done anything against the law. My life was football, for 45 years with FIFA. My life is football."

Platini, a former UEFA President, also said he was confident, and joked he would have to take a course in German so he could follow the proceedings.

"I am convinced that justice will be fully and definitively done to me after so many years of wild accusations and slander," he said in statement before the trial began.

"We will prove in court that I acted with the utmost honesty, that the payment of the remaining salary was due to me by FIFA and is perfectly legal."

The Swiss Office of the Attorney General (OAG) has accused Blatter and Platini of "fraud, in the alternative of misappropriation, in the further alternative of criminal mismanagement as well as of forgery of a document.

Platini, the former UEFA president who as a player captained France to victory in the 1984 European Championship, was also charged as an accomplice.

Blatter, 85, and Platini, 66, were both banned in 2016 from football for six years over the payment, made with Blatter's approval for work done a decade earlier.

"FIFA has brought a civil action against both Blatter and Platini to have the money which was illegally misappropriated repaid to FIFA so it can be used for the sole purpose for which it was originally intended: football," FIFA's lawyer Catherine Hohl-Chirazi said.