Motosport Italia, which runs WRC Team Mini Portugal, announced last week that Araujo's replacement would allow the driver to 'regain his focus,' after hurting his back in a heavy landing on Rally Finland.
But Araujo, a two-time Production World Rally Champion, insists that the team's announcement about his injury was misleading and has passed on details of his 'unfair' dismissal to the FIA.
In his own statement, Araujo said: "During a test in Germany on August 10-12, I was not allowed to test the car and instead was put under pressure to declare myself 'sick' and not to take part in Rally Germany. At the time I could not believe I was receiving such a proposal.
"Then, on August 15, Motorsport Italia requested permission to use the licence of WRC Team Mini Portugal - which belongs to my company - to be used with another driver until the end of the season. I declined, and the next day they informed me that I am no longer the driver without any justification or valid explanation.
"On August 17, I informed Motorsport Italia, Mini Germany and Mini Portugal that I have collected all necessary documentation about this matter and delivered it to my team of lawyers, who will take all necessary legal actions to protect my name and that of the project that I respect enormously. These facts have also been reported to the FIA.
"All my sponsors have been informed and support me entirely on my decision to take this matter to legal action. We have agreed to remove all the advertising of car #12 if WRC Mini Team Portugal."
Araujo, who lies 13th in the WRC points, said that there have been several other incidents during the year that have soured the relationship between himself and the team.
"From Rally Mexico onwards, the team has attempted to camouflage all the technical problems and blame the faults on the drivers, myself and Paulo Nobre," he added.
"They have tried to object to all my press releases, which were all approved by Mini Portugal and never gave any negative references to them."