ZURICH (AP) — FIFA investigators are yet to be convinced there was any long-standing verbal agreement that led to Sepp Blatter secretly sanctioning the payment of 2 million Swiss francs (about $2 million) to Michel Platini.

Failing to persuade FIFA's ethics committee that the 2011 payment was legitimate led to Blatter, the FIFA president, and Platini, the head of European soccer, both being suspended for 90 days on Thursday, pending a full verdict. Both strongly deny any wrongdoing, want to see the reasons for the suspensions and have filed appeals.

The case has removed - temporarily at least - two of the most powerful men in the game in the latest escalation of a corruption scandal that has rapidly expanded since May, when the U.S. indicted 14 officials, seven of whom were arrested in Zurich while attending the FIFA Congress.

Although FIFA's ethics committee does not have to prove a motive for Platini's payment — unlike the Swiss attorney general — they have been exploring whether there was any connection to it being made months before Blatter gained UEFA's support in the 2011 FIFA presidential election, a person familiar with the situation told AP.

The person spoke on condition of anonymity because the investigation by FIFA's ethics committee, which could lead to lengthy bans from soccer for Blatter and Platini, is still continuing in private.

Here is a deeper look into the issues being investigated by FIFA around the payment:

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WHY AND WHEN WAS IT MADE?

Platini received his 2 million Swiss franc (about $2 million) windfall in February 2011, supposedly after calling in a debt from his time on the FIFA payroll as an adviser to Blatter between 1998 and 2002.

At the time, Platini received 300,000 Swiss francs per year to travel the world with Blatter, another person familiar with the FIFA ethics case told the AP on Monday. Platini carried out the job for 3 1/2 years, collecting 1.05 million Swiss francs, before being elected to the ruling executive committees at both UEFA and FIFA in 2002.

What Platini now claims, which is yet to be publicly endorsed by any FIFA staffers from 1998 to 2002, is that he deferred an additional 500,000 Swiss francs per year from the job agreement until the governing body could afford to pay him.

Although FIFA did forecast a deficit of 134 million Swiss francs between 1999 and 2002, the accounts show a revenue surplus of 115 million Swiss francs by the end of the period, meaning it could have afforded to pay Platini.

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WAS THE PAYMENT LEGITIMATE?

The Swiss attorney general is suspicious. That is why his investigators swooped on FIFA headquarters as Blatter was chairing an executive committee meeting in September and immediately quizzed the FIFA president as a suspect on allegations that he sanctioned a "disloyal payment" to Platini.

Platini has a lower status in the Swiss criminal investigation, being treated as somewhere between a witness and an accused person.

Separately, FIFA's ethics investigators received the documents that form the Swiss criminal investigation and conducted hours of interviews with Blatter and Platini. The fact they decided they should be banished from soccer — for 90 days at least while the investigation is completed — is a signal of their early assessment of the case.

Blatter is yet to say anything himself or through his lawyers to publicly support Platini's account, while denying any illegality himself. Differing explanations are said to have been given during their interviews and contradictions in their accounts will only deepen the possibility of long bans.

Verbal agreements for such large amounts would not be sanctioned in the corporate world in most countries.

One aspect of the case considered within FIFA as implausible is how Platini expected to call in the debt after 2002 if Blatter was either voted out of power, quit or was no longer alive.

Also being considered is how Platini expected to demand payment, without paperwork, if he had fallen out with Blatter after 2002 or the president had simply refused? The outstanding amount, as Platini claims, could have provided Blatter with enormous hold over the former France captain. And could it have weakened Platini's determination to take on Blatter, knowing 2 million Swiss francs was potentially at stake?

That is why investigators have delved into the timing of the payment — February 2011 — around four months before Blatter was re-elected for a fourth term.

A month before the vote, Platini's UEFA said it "strongly recommends" that European associations vote for Blatter. The incumbent was facing one challenger until Mohamed bin Hammam withdrew days before the poll after becoming embroiled in a bribery case.

Platini insisted two weeks ago in quotes provided by UEFA: "The fact that this payment was made a few months before the FIFA presidential elections is irrelevant since I never had any plans of becoming a candidate."

A rift has grown between Platini and Blatter recently over the 79-year-old Swiss blocking the 60-year-old Frenchmen's path to the FIFA presidency.

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WHY IS THE PAYMENT ONLY EMERGING NOW?

Few people in 2011 are likely to have known about the payment, beyond Platini and Blatter, the person familiar with the case said Tuesday.

The Swiss attorney general will have discovered the payment either from a whistleblower, or from the more than 120 suspicious activity reports from Swiss banks or from the 11 terabytes of FIFA data seized from FIFA HQ.

Details were then passed to FIFA's ethics investigators to ensure it could speedily conduct a case into Blatter, world football's leader of 17 years, and Platini, who has headed UEFA since 2007.

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UEFA DECISION DAY

Hours after Platini was suspended on Thursday, UEFA declared that its executive committee "stands fully behind" Platini following a teleconference of members.

But ahead of an emergency meeting of the executive committee on Thursday, cracks are showing within UEFA, sparked by Danish member Allan Hansen expressing frustration that he is yet to receive replies to many questions about the payment. His support for Platini would end if no written contract exists — which it does not.

When questions about Platini's probity come up in Thursday's meeting in Nyon, Switzerland, it will be Hansen who is likely to be able to speak with some authority on the issue. That is because he is also a member of FIFA's audit and compliance committee, which was established in 2012.

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FUTURE OF BLATTER AND PLATINI

The 90-day suspensions, which can be extended by 45 days, were imposed to remove Blatter and Platini from positions of power. The punitive sanctions, which could last years, would be implemented by FIFA's ethics committee following guilty verdicts — mostly likely before the Swiss criminal investigation reaches its conclusion.

While the criminal case requires the attorney general to prove intent, the FIFA ethics code does not and the threshold for convictions within the sport is much lower.

The code in place in 2011 says that sanctions can follow acts being "committed deliberately or negligently." Blatter was ultimately responsible for FIFA when the payment was made and Platini was a fellow member of his ruling committee, whose other members did not know about the transaction.

If FIFA ethics judge Hans-Joachim Eckert accepts there was a verbal agreement, Blatter and Platini could still be facing multi-year bans. If Eckert does not believe them, the payment could have been deemed corrupt and result in life bans.

Blatter's career was coming to an end anyway but his disgrace will be complete if an absolute ban is the final chapter of a 40-year FIFA career. Blatter was planning to stand down in February after an emergency election prompted by his decision to stun soccer on June 2 with a resignation statement following the arrest of close associates.

Platini, though, had his eyes on Blatter's FIFA seat. Now it seems highly unlikely Platini will ever lead world soccer, his reputation as a title-winning playmaker for France and Juventus threatening to be wrecked by the case.

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