The Formula 1 governing body has parted ways with its interim general secretary Shaila-Ann Rao less than six months after appointing her.
An FIA statement said Rao had joined to assist new president Mohammed Ben Sulayem in his “transition period”.
He said she was leaving because “this period is now coming to an end”.
However, senior sources have told BBC Sport that the decision to leave the FIA was hers – she quit because the job was not what she expected.
Sulayem, who took over the presidency of the FIA last December, said: “Shaila-Ann has been a great support to me when it comes to Formula 1, always acting with professionalism and integrity.”
Rao joined the FIA in June from her previous role as special adviser to Mercedes F1 team principal Toto Wolff.
His links with Mercedes have raised concerns at Ferrari and Red Bull.
In particular, at the height of the cost cap row, Red Bull raised questions about Rao and whether they had been targeted.
Red Bull team principal Christian Horner says it was Rao who called him shortly after Max Verstappen clinched his second world title at the Japanese Grand Prix to officially tell him that Red Bull had been found guilty of breaching the financial regulations.
The FIA found that Red Bull had exceeded the $145m (£114m) cost cap by £1.86m. Their penalty was a $7m (£5.9m) fine and a 10 per cent reduction in their authorized aero research allowance.
Sulayem was asked about Rao’s future during the Abu Dhabi Grand Prix last weekend. He hinted that she would be leaving the FIA, saying: “Her position is that of acting general secretary. What does acting mean?”
But he added: “Shaila-Ann has been very supportive of me and I see her intelligence on big decisions. I will stand up for my people.
“As for Shaila-Ann, there has been an accusation that she is primarily a Mercedes supporter.
“In fact, when the penalties were there, she said, ‘It’s a bit harsh.’ And I said, ‘God, there’s someone accusing her of being with Mercedes and she’s telling me that’s hard.'”