Sepp Blatter was first elected FIFA president in 1998
A Swiss prosecutor on Thursday concluded four days of final interviews with former FIFA president Sepp Blatter in a long-running probe into a suspected fraudulent payment in 2011.
Former world football chief Blatter, 85, has met with a federal prosecutor every day since Monday for final hearings in a case that shook the sport.
Blatter is being investigated over a two million Swiss franc ($2.2 million, 1.85 million euro) payment to Michel Platini, who was then in charge of European football's governing body UEFA.
The final hearings with a federal prosecutor from the Office of the Attorney General (OAG) of Switzerland took place in Zurich, where FIFA has its headquarters.
Blatter was accompanied by his lawyer Lorenz Erni.
"It's over. It was the last day," Blatter's spokesman Thomas Renggli told AFP after Thursday's fourth straight day of interviews.
"At the end of the hearing, Mr. Erni said now is the time to stop harassing Mr. Blatter.
"Now Mr. Blatter is relieved. He's glad it's over. It was hard for him this week, mentally and physically."
Due to Blatter's fragile health, he could only stay at the hearing venue for a couple of hours maximum at a time.
While 66-year-old Platini's final interview with the prosecutor was in March, Blatter's hearing was postponed to August due to the retired Swiss football administrator's health.
He spent two months in hospital in December and January after undergoing heart surgery.
Under the Swiss Code of Criminal Procedure, in lengthy and complex proceedings, suspects "are questioned one last time before the investigation is concluded", the OAG said in a statement ahead of the final hearings.
Joseph "Sepp" Blatter joined FIFA in 1975, became its general secretary in 1981 and the president of world football's governing body in 1998.
He was forced to stand down in 2015 and was banned by FIFA for eight years, later reduced to six, over ethics breaches for authorising what prosecutors termed a "disloyal payment" to Platini -- in other words, one made in his own interests rather than FIFA's.
"The criminal proceedings against Joseph Blatter are now being conducted on suspicion of fraud, breach of trust and unfaithful business management," the OAG statement said.
"The criminal proceedings against Michel Platini are being conducted on suspicion of fraud, participation in breach of trust, participation in unfaithful management and false documents."
The OAG said the presumption of innocence applied to all parties and it could not put a time frame on concluding the investigation.
"Conducting final interviews does not allow any conclusions to be drawn about the outcome of criminal proceedings (discontinuation, penalty order or indictment)," it added.
Renggli said a decision on an indictment or a dismissal could come within the next few weeks.
In a statement before this week's final hearings, Blatter insisted the payment to former France and Juventus attacking midfielder Platini, considered among world football's greatest-ever players, was above board.
"It was based on an oral contract that regulated Platini's advisory activities for FIFA between 1998 and 2002," he said.
"The payment was delayed because FIFA was initially unable to pay out the entire amount -- and Platini only made the claim in 2010.
"The process was correctly declared as a late payment of wages, the social insurance was accounted for accordingly and finally approved by all responsible FIFA bodies."