The People quoted the Manchester United boss as saying: "He told us at the time of negotiations that he was only going to play for four more years.”
A representative for Tevez has denied the claims, adding that the 27-year-old plans to play for a further eight years.
Meanwhile, a Manchester United spokesman explained that Ferguson was referring to the player returning to Argentina as opposed to retiring.
Tevez has gone public with his desire to leave Eastlands and move closer to his family in South America.
A reported £40m offer from Brazilian side Corinthians fell through earlier this month due to transfer deadline restraints.