The cheap ticket perk is part of Pierre-Henri Gourgeon's severance package from the airline, which he left in October 2011.
Every current and former Air France employee has the right to tickets at reduced rates, but the €24 cost was exceptionally low.
"To travel in business class to Mauritius would cost an ordinary Air France employee €745," said a union leader.
"There's also an embargo usually on flights to Mauritius at this time of the year which was lifted for the Gourgeon family," said another source, reported French daily Libération.
The issue caused strong reactions as it came at the time when Air France-KLM is planning €2 billion of savings and changes in contracts of its employees.
"It's a scandal," said a pilot, who preferred to remain anonymous. "Mr Gourgeon was paid more than a million euros a year and he can't buy his own tickets?"
By the end of the day, Gourgeon had decided to change his tickets and pay the regular rate open to all Air France staff.
A spokesperson for the airline said he had done this out of "solidarity with the employees of this company to which he remains very attached."