FIFA President Sepp Blatter addresses during the preliminary draw for the 2018 FIFA World Cup at Konstantin Palace in St. Petersburg, Russia July 25, 2015. [Photo/Agencies]

ZURICH - Swiss prosecutors have opened a criminal investigation into Joseph Blatter, the head of world soccer body FIFA, on suspicion of criminal mismanagement and misappropriation, the Swiss attorney general's office (OAG) said on Friday.

As the corruption probe at FIFA widened, OAG representatives interrogated Blatter after FIFA's executive committee met in Zurich, the OAG said in a statement.

"Furthermore, the OAG conducted on 25 September 2015 a house search at FIFA Headquarters with the support of the Federal Criminal Police. The office of the FIFA President has been searched and data seized," it added.

FIFA said it would continue to cooperate with Swiss authorities, shortly after the announcement.

"Since 27 May 2015, FIFA has been cooperating with the Office of the Swiss Attorney General (OAG) and has complied with all requests for documents, data and other information. We will continue this level of cooperation throughout the investigation," Zurich-based FIFA said in a statement.

"Today, at the home of FIFA, representatives from the Office of the Swiss Attorney General conducted interviews and gathered documents pursuant to its investigation. FIFA facilitated these interviews as part of our ongoing cooperation."