No written contract for the ?1.35million payment made to Michel Platini by FIFA in 2011 for work carried out more than nine years beforehand has been provided to investigators probing the case, it has emerged.
The payment, signed off by FIFA president Sepp Blatter, appears to have been paid solely on the basis of an oral agreement, sources with knowledge of the case have confirmed to Press Association Sport.
Platini did submit an invoice to FIFA in February 2011 and was paid 2million Swiss francs. The UEFA president has said Blatter informed him when he started as his advisor in 1999 that it was not initially possible to pay him "the totality of my salary because of FIFA's financial situation at that time".
A written contract does exist covering three and a half years until 2002 for Platini to be paid 300,000 Swiss francs annually, and accounts show he was paid a total of 1.05million Swiss francs. However no written contract has been produced which covers the 2million Swiss franc payment made in 2011.
Swiss law also states that even if there was a written contract, any overdue payment has to be made within five years.
The Swiss attorney general has launched criminal proceedings against Blatter into what was described as a "disloyal payment" to Platini, and both men have been provisionally banned by FIFA's ethics committee pending investigations into the payment. Both have formally appealed against the ban to FIFA's appeals committee.
The case has left Platini's hopes of succeeding Blatter as FIFA president in tatters. Nominations close on October 26, but the French football federation is expected to go to the Court of Arbitration for Sport to argue that its candidate is being prevented from standing because of the provisional ban.
An emergency meeting of FIFA's executive committee on October 20 is also due to discuss whether the presidential election on February 26 should be postponed.
Blatter and Platini have strenuously denied any wrongdoing.
Platini said last week: "Mr Blatter informed me when I started my role as his advisor that it was not initially possible to pay the totality of my salary because of FIFA's financial situation at that time.
"I never doubted, however, that the remaining amount owed to me would be paid eventually, so I did not actively pursue it.
"I even put the matter to the side for a while, before finally requesting that the outstanding balance was paid in 2011."