Switzerland's attorney general is prepared for his investigation into the bids for the 2018 and 2022 FIFA World Cups to cause "collateral" damage to the host nations if wrongdoing is proved.

Michael Lauber said his investigators are probing 53 possible money-laundering incidents as part of their probe but that the investigation could take years, such is the volume of computer data to be examined.

Lauber did not rule out FIFA president Sepp Blatter or secretary general Jerome Valcke being interviewed as part of the investigation.

Asked about the effect of the investigation on the hosts - Russia in 2018 and Qatar in 2022 - Lauber told a news conference in Bern: "I don't mind if this has collaterals somewhere else. I don't care about the timetable of FIFA - I only care about my own timetable, which is following Swiss procedural code."

The probe follows the report by FIFA's ethics investigator Michael Garcia being passed by the world governing body to the attorney general. Russia and Qatar have both denied any wrongdoing.

The head of the white-collar crime division at the Swiss Office of the Attorney General (OAG) has been appointed to lead a task-force carrying out the investigation.

Lauber said: "There will be formal interviews of all relevant people. By definition, this does not exclude interviewing the president of FIFA and/or its secretary general.

"Our investigation is of great complexity and quite substantial. The OAG has seized around nine terabytes of data.

"You find in the task-force specialised and experienced prosecutors, experts in mutual legal assistance and a specialized forensic IT team from the Federal Criminal Police.

The head of the white-collar crime division at the Swiss Office of the Attorney General (OAG) has been appointed to lead a task-force carrying out the investigation.

Lauber said: "There will be formal interviews of all relevant people. By definition, this does not exclude interviewing the president of FIFA and/or its secretary general.

"Our investigation is of great complexity and quite substantial.

"You find in the task-force specialised and experienced prosecutors, experts in mutual legal assistance and a specialized forensic IT team from the Federal Criminal Police.

"We note positively that banks in Switzerland did fulfill their duties to file suspicious activity reports. 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. The procedure is huge and complex on many levels."

Lauber said the investigation was separate from the FBI's football corruption probe which saw seven FIFA officials arrested in Zurich last month and which has indicted 18 people.

"The Swiss investigations are executed independently from the prosecutions of our US colleagues. Therefore, documents and data of our Swiss investigation will not be shared automatically with the US counterpart. The exchange of information has to respect the binding rules of mutual legal assistance."

Lauber refused to give a time-scale but said it could take years to complete the investigation.

He said: "The world of football needs to be patient. By its nature, this investigation will take more than the legendary 90 minutes.

"Be assured - the OAG will give priority to this case and will act according to the principles of the rule of law."