Swiss prosecutors are probing into 53 cases related to money laundering, while investigating into FIFA's handling of bids for the 2018 and 2022 World Cups, officials stated on Wednesday.

Terming the cases as "suspicious," Attorney general Michael Lauber said that they had been reported by banks and involved a "huge and complex" inquiry into the football's world body. The cases could take months if not years to be solved, he said.

"We note positively that banks in Switzerland did fulfil their duties to file suspicious activity reports," he told.

"Partly in addition to the 104 banking relations already known to the authorities, banks announced 53 suspicious banking relations via the Anti-Money-Laundering-Framework of Switzerland," he added.