Several members of FIFA's executive committee have already been questioned by the Swiss justice, and president Sepp Blatter could also be quizzed "in the future if needed", a spokesman for the Swiss public prosecutor said.
"The OAG (Office of the Attorney General) is questioning those FIFA Executive Committee members who are not Swiss residents who voted back in 2010 (when the 2018 and 2022 World Cups were awarded to Russia and Qatar) and are still in office," spokesman Andre Marty told AFP.
"The president of FIFA will not be questioned at this point of time. If need be he will be questioned in the future," Marty added.
Seven senior FIFA officials meet these criteria -- Confederation of African Football (CAF) president Issa Hayatou (Cameroon), Angel Miguel Villar Llona (Spain), Michel D'Hooge (Belgium), Senes Erzik (Turkey), Marios Lefkaritis (Cyprus), Hany Abo Rida (Egypt) and Vitaly Mutko (Russia).
Swiss authorities appear to have prioritised questioned officials living outside Switzerland for practical reasons as they were attending FIFA's Executive Committee meeting in Zurich on Saturday.
Two other current members of the Executive Committee who voted in 2010 live in Switzerland -- Blatter and UEFA president Michel Platini.
The Swiss justice spokesman said the leaders were interviewed as "people who could provide information" in the criminal investigation into the awarding of 2018 and 2022 World Cups, without giving further details.
This investigation had been opened two months ago, at the request of FIFA, but was only revealed this week as corruption scandals rocked the supreme body of world football during elections for the presidency. Asked about the case of Blatter who was re-elected Friday for a fifth term as president, the spokesman replied: "The FIFA President will not be questioned at this stage. If necessary, he will be in the future."
Marty was reacting to claims by British newspaper The Sunday Times whereby Blatter should be interviewed by the Swiss justice along with nine other top FIFA officials.
Another investigation lead by the US justice system has also targetted FIFA. As part of this investigation, seven FIFA officials were arrested Wednesday in their Zurich hotel. All seven are fighting their extradition to the United States.
