FIFA president Sepp Blatter was set to face the media on Friday, as the scandals that surround him widen at a seemingly relentless pace.

Blatter's press conference following FIFA's executive committee meeting was always going to be closely watched, with both the US and Swiss justice departments carrying out major investigations into corruption at world football.

But events over the last two weeks have raised the stakes.

On Thursday, Switzerland's Attorney General Michael Lauber's office said FIFA had agreed to hand over the emails of suspended secretary general Jerome Valcke, evidence Lauber had demanded as part of an investigation into World Cup bidding.

That announcement came hours after Lauber's office said FIFA had indicated it would only hand over the emails if certain conditions were met.

Those conditions were not disclosed and there was no comment as to what ultimately led FIFA to unseal the emails.

FIFA said only that it "fully supports" the Swiss investigation and had cooperated with the attorney general since his inquiry was launched in May.

A week before FIFA agreed to the email release, football's governing body put the Frenchman on indefinite leave over accusations he agreed to let World Cup tickets be sold at vastly inflated prices.

Valcke, who had been Blatter's right-hand man, fiercely denies the allegations.