French newspaper Journal du Dimanche reported on Sunday that it possesses a copy of a document which it describes as "resembling an intelligence service memo".
It reports that the document was distributed during a Uefa executive committee meeting in the Swedish capital Stockholm on November 12th 1998.
The document indicates that Sepp Blatter — who was elected Fifa president for the first time in June 1998 — "already announced that Platini would become the future sporting director of Fifa. Platini would therefore become part of Fifa."
It added that there were rumours that the Frenchman "wishes to work from Paris" and that "there has been talk about one million Swiss francs as salary".
That meeting was attended by the then Uefa president, the Swede Lennart Johansson, as well as the Germans Egidius Braun and Gerhard Aigner, the Italian Antonio Matarrese, the Turk Senes Erzik and the Norwegian Per Ravn Omdal.
Three of them — Johansson, Matarrese and Erzik — are also members of Fifa, according to the Journal du Dimanche.
Johansson lost out to Blatter in the 1998 election for the Fifa presidency, with Platini giving his backing to the latter.
The current Uefa president Platini, along with Blatter, was handed a provisional 90-day ban from all football activities on October 8th while an investigation was held into a suspect payment of $2-million paid by the latter to the Frenchman in 2011 allegedly for work carried out in 2002.
A source close to Fifa revealed on Friday that the Fifa ethics committee will question Platini on the affair "most likely between December 16th and 18th".
Platini's lawyer Thibaud d'Ales said at the end of November that the ethics body's investigatory chamber wants the Uefa chief banned for life.
The 60-year-old former France great had previously been the favourite to become the next Fifa president when Blatter officially stands down and an election is held in February, and his lawyer is hopeful this document can help Platini clear his name.
"This document is written proof of a verbal contract. The document not only confirms the existence of a work contract between Michel Platini and Fifa in 1998, but also the amount (of money)," D'Ales told AFP.
"It demonstrates that there was nothing occult about this contract and that several members of Uefa's executive committee, and several members of Fifa's executive committee, were aware of it in 1998."
He also stated his belief that the accusations levelled against Platini are "unfounded" and that he would eventually be cleared.
Platini has appealed against his suspension at the Court of Arbitration for Sport (CAS).
In the meantime, Platini cannot begin lobbying for the FIFA presidency.
But if his suspension is overturned by the CAS, Platini could attend next Saturday's draw in Paris for the Euro 2016 finals.
Asian football chief Sheikh Salman Bin Ebrahim Al Khalifa, former Fifa vice president Prince Ali bin Al Hussein of Jordan, former Fifa official Jérôme Champagne of France, South African businessman and former minister Tokyo Sexwale and Uefa general secretary Gianni Infantino are the five confirmed candidates to succeed Blatter.