Sepp Blatter and Michel Platini, who was favourite to succeed the Fifa president until a dramatic intervention by the Swiss attorney general, are both now understood to be under formal investigation by Fifa’s independent ethics committee and could be suspended within days.

If Platini was provisionally suspended while Fifa’s investigatory continued to look into the issues raised by the Swiss attorney general when criminal proceedings were opened against Blatter on Friday, he would be automatically ruled out of the presidential race.

Platini, who cooperated with Swiss investigators by answering questions on a two million Swiss francs payment from Blatter, that was said to be made to the detriment of the world governing body, has said he was owed the money from a contract with Fifa between 1999 and 2002 but has not explained why it took nine years for the invoice to be paid. It is understood that Fifa investigators, headed by Cornel Borbély, have formally opened files on both men and are expected to liaise with the Swiss attorney general.

Criminal investigation is ‘righteous justice’ for former Fifa president Sepp Blatter, says investigative journalist. Guardian

While they were already looking into some issues raised, including a 2005 World Cup television rights deal between Fifa and Jack Warner, the former head of the Confederation of North, Central American and Caribbean Association Football, that was signed off by Blatter, the matter of the 2011 payment to Platini was not among them.

They will interrogate both Blatter and Platini before deciding within days whether to issue a provisional suspension. One source said there was “no way” Platini, who fell out with the long-standing Fifa president when he reneged on an agreement to step down in 2011, could stand if he was suspended.

Even if he is not suspended, the French Uefa president faces the prospect of a so-called integrity check by the same ethics committee before he is allowed to submit his candidature on 24 October.

If Blatter were suspended, it is assumed he would stand down immediately given that he has promised to do so anyway in February.

Prince Ali bin al-Hussein, the Jordanian FA chief who was beaten to the presidency by Blatter in May and was an outsider to win next February’s election before Friday’s dramatic events, said he had heard from many of Fifa’s 209 member associations since Blatter was questioned and his computers seized.

“Change, as I have always said is a process. It is not an event. The process of change at Fifa began in May,” he said.

“We have an opportunity in February to carry that momentum forward. We must come together and work to restore Fifa’s credibility and reputation by bringing about the change that is so clearly needed.”

However, others outside Fifa including Transparency International maintain that Prince Ali is also compromised by his four-year spell on Fifa’s executive committee and continue to call for an independent root and branch governance review.

Clive Efford, the shadow sports minister, said: “That Sepp Blatter has been allowed to stay on at the helm of Fifa, despite the numerous scandals he has been mired in, raises serious concerns about the organisation’s ability to tackle corruption. It is time to end the Blatter era and the corruption that came with it.”