Fifa president Gianni Infantino is to be interviewed by ethics investigators following allegations he breached the governing body's code of ethics.
BBC Sport has learned Infantino will meet Robert Torres, a member of the investigatory chamber of the Fifa ethics committee.
The interview in Zurich - possibly as early as Friday - is part of a preliminary probe.
If there is sufficient evidence then a full investigation could be opened.
Under such circumstances Infantino could be suspended from his role for up to 90 days.
The allegations relate to a possible conflict of interest when using private jets laid on by a World Cup-bidding country; that he filled senior posts without checking people's eligibility for the role; and billing Fifa for mattresses, flowers, an exercise machine and personal laundry.
A Fifa spokesperson told BBC Sport: "The Fifa president has stated publicly he fully respects the independence and work of the ethics committee and that he would provide, if required, whatever information necessary to facilitate any potential review by the committee.
"The president has made clear that he has acted appropriately and in accordance with Fifa's code of ethics."
Infantino is said to be "very confident" that no further action will be taken with sources close to the former Uefa secretary general describing the allegations as "absurd" and "baseless".
External legal counsel is said to have been hired by Fifa to provide an independent assessment of the claims against Infantino. It is believed to have concluded he has no case to answer.
The same sources have described the allegations as part of a "vendetta" against Infantino by unnamed people who have recently left Fifa. Documents, it is claimed, have been deliberately leaked in order to destabilise the man elected to the top job in world football in February.
Fifa has been hit by a spate of high profile departures in recent months.
Domenico Scala resigned as Fifa's head audit and compliance in May while the governing body's one time finance director and acting secretary general, Markus Kattner, was sacked that same month amid allegations of financial impropriety.
Kattner was fired after the discovery of a secret bonus scheme which paid him millions of dollars over a period of years.
A number of other employees have left, or are expected to leave, following a major restructuring within Fifa's Zurich headquarters.
A further 18 potential witnesses are understood to have been questioned as part of the preliminary probe into Infantino.
Torres is said to be leading the investigation given that the chairman of the ethics investigatory chamber, Cornel Borbely, and Infantino are both Swiss nationals.
The interview by investigators follows the leaking, to German media, of an internal Fifa memo.
Infantino was alleged by an unnamed Fifa insider to have used private jets during a trip to visit the 2018 and 2022 World Cup hosts Russia and Qatar, raising questions of a potential conflict of interest.
Fifa organised the flight to Moscow but an airline transfer to Doha was not available following a late change in the schedule by his Russian hosts.
Infantino and his staff then travelled by private jet, arranged by the Russians. The Gulf state in turn organised the return trip to Switzerland.
There have also been reports in Swiss and German media that Infantino, after attending the Champions League Final in Milan in May, flew on to Rome for an audience with the Pope. He then returned to Geneva.
But sources say that flight will be argued not to be a breach of Fifa's code of ethics given it was a private arrangement with a family friend who is unconnected to football.
The leaked internal document also alleges that Infantino demanded Fifa hire an external driver, who then billed the governing body for driving Infantino's family and advisors around while he was abroad.
It also details costs authorised by Infantino of:
•£8,795 for mattresses at his home
•£6,829 on a stepper exercise machine
•£1,086 for a tuxedo
•£677 on flowers
•£132 on personal laundry
It also makes reference to how many of the candidates chosen by Infantino to fill senior posts had not passed the relevant eligibility checks, including the new Fifa secretary general, Fatma Samoura.
But Infantino believes the case will be dismissed given the relevant facts.
For example, it's understood Infantino wanted a bed removed from an office space previously occupied by Sepp Blatter. The former Fifa president is understood to have been partial to an afternoon nap on occasion.
In its place Infantino asked for a step machine, with an expectation one would be brought in from Fifa's on-site gymnasium.
Instead, officials purchased a new one with the resultant invoice being used by Infantino's enemies, according to sources, to damage him.
The Swiss-Italian is also under pressure for failing to sign an employment contract, with reports of a dispute between him and Scala, who helped set pay levels, over his salary.
A spokesman for Fifa's investigatory chamber declined to comment "on possible preliminary investigations."
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