Tim Mayer has spoken out against FIA president Mohammed Ben Sulayem's leadership after the long-serving steward was sacked, alongside deputy Formula Two race director Janette Tan.

The FIA's leadership has been constantly criticised this season, and the sport's governing body has been rocked by a string of key departures.

Ahead of the Las Vegas Grand Prix, Niels Wittich and compliance officer Paolo Basarri both departed and according to a report from BBC Sport, Mayer's exit has been followed by Tan, who was set to take over as F2 race director for the final two rounds.

Mayer was baffled by the decision to let Tan go. "She is the epitome of the type of person we want working for the FIA, the best of the next generation of race directors," he told the BBC. "I don't know the circumstances, but one would think they would work very hard to keep someone of her character."

With Tan out of the picture, F1's new race director, Rui Marques, will have to work F1, F2 and F1 Academy at the Qatar Grand Prix this weekend, putting him under immense pressure.

Mayer, who is a sporting organiser of the three US races on the calendar, believes he was fired because Ben Sulayem was personally offended by a right to review document filed by the Circuit of the Americas after they were hit with a fine for a track invasion back in October.

"The official reason that will be given is they felt there was a conflict of interest with the FIA as I had led the right of review in my role as organiser," Mayer explained.

"But that is not why I was fired. Being an organiser is a role that I have fulfilled, benefiting the FIA, for over 12 years. This isn't new. In spite of the matter being resolved quietly and amicably, he's still upset and decided to fire me.

"After 15 years of volunteering my time as a steward, a decade teaching other stewards and hundreds of hours volunteering in other roles, I got a text from one of his assistants."