Embattled Sepp Blatter was urged to stand down as FIFA president on Saturday after he was placed under a criminal investigation as his heir-apparent Michel Platini also came under scrutiny over a murky multi-million-dollar payment.

In a dramatic escalation of the corruption scandal engulfing world soccer, Swiss investigators accompanied by Swiss police swept into FIFA’s headquarters on Friday as their attention turned to Blatter and Platini.

“Swiss criminal proceedings against the President of FIFA, Mr. Joseph Blatter, have been opened on September 24, 2015 on suspicion of criminal mismanagement…and – alternatively – misappropriation,” said a statement from Switzerland’s attorney general’s office (OAG).

This stunning development came after months of probes following raids in Zurich which led to the indictment of more than a dozen top officials.

Prince Ali bin al Hussein, a candidate to succeed Blatter, said the suspicions of criminal mismanagement against FIFA’s veteran leader highlighted “the need for new leadership that can restore the credibility of FIFA”.

Swiss prosecutors said Blatter was being investigated over the 2005 sale of World Cup television rights to the Caribbean Football Union, then run by his former ally Jack Warner, a deal which had been “unfavorable for FIFA”.

Blatter was also suspected of a “disloyal payment” of two million dollars to Platini in February 2011 allegedly made for work the Frenchman carried out for FIFA between 1999 and 2002, before he was elected head of UEFA.

Saturday’s headlines in the Swiss press made uncomfortable reading for the beleaguered Blatter.

“Blatter should go as quickly as possible” was the blunt advice given to the 79-year-old football strongman by Neue Zurcher Zeitung.

Blick’s front page headline was bleaker: “Blatter risks jail….Twilight years behind bars?”

– Platini blow –

Swiss authorities said Blatter was questioned as “a suspect”, while Platini had been quizzed “as a person called upon to give information”.

Blatter’s lawyer Richard Cullen stressed that the FIFA boss was cooperating with Swiss authorities and that a review of the evidence would show “no mismanagement occurred”.

Platini defended the payment he received in 2011, made three months before the Frenchman announced he would not challenge Blatter for re-election during that year’s race for the FIFA presidency.

“Concerning the payment that was made to me, I wish to state that this amount relates to work which I carried out under a contract with FIFA,” said the UEFA boss.

But he offered no explanation as to why the payment had arrived almost a decade after the work had been completed.

A former FIFA insider, who requested anonymity, told AFP that Platini’s hopes of being elected to replace Blatter next year had been damaged by Friday’s revelations.

“Platini took a serious blow” by even being mentioned in the Swiss statement, the source told AFP.

Blatter “is finished now … Platini will struggle to recover from being questioned”.

Platini is a former Blatter ally who turned against the veteran Swiss sports baron over the past 18 months as FIFA’s troubles mounted.

The investigation is also into Blatter’s links with Warner, a former FIFA vice-president now at the centre of a US investigation.

– ‘Unfavorable to FIFA’ –

The attorney general said Blatter was suspected of making a deal “unfavorable to FIFA” with the Caribbean Football Union, which Warner used as his power base.

Warner is one of 14 soccer officials and business executives charged by US prosecutors of involvement in more than $150 million in bribes for football broadcasting and marketing deals.

Nearly all of the suspects are from central and South America. Until recent days, FIFA’s top leadership had escaped accusations flying around the world body, which earns $5 billion from the World Cup.

Blatter was re-elected to a fifth term at FIFA’s congress in May in Zurich despite the arrest of seven officials but then announced on June 4 that he would stand down.

Unless forced out before he is due to step down in February.

FIFA this month suspended Blatter’s right-hand man Jerome Valcke after he was accused of involvement in an accord to sell tickets for the 2014 World Cup at inflated prices. He denies the accusation.

Prince Ali says football must now look to a scandal-free future.

“We cannot change the past, but we can have a future where FIFA member associations are able to focus on football rather than worrying about the next scandal or criminal investigation involving FIFA leadership,” he said.