Niels Wittich has left his role as Formula 1’s race director with immediate effect.
The German, a replacement for Michael Masi in 2022, “has stepped down from his position to pursue new opportunities,” the FIA said in a statement to BBC Sport.
He will be replaced from the next race in Las Vegas by Rui Marques, most recently the race director for Formula 2 and 3.
The surprise move has happened quickly. FIA staff were told earlier on Tuesday, BBC Sport has been told.
An FIA spokesperson said: “Niels has fulfilled his numerous responsibilities as race director with professionalism and dedication. We thank him for his commitment and we wish him the best for the future.
“Rui brings a wealth of experience having previously served as track marshal, scrutineer, national and international steward, deputy race director and race director in various championships.”
It is highly unusual for an F1 race director to be changed in the middle of a season, especially given there are just three races remaining.
The decision was not widely expected within F1, although some insiders had heard Wittich would be replaced at the end of the season. No full explanation for it has been provided by the FIA.
Wittich is the latest in a series of senior people to leave the FIA in the past year.
Sporting director Steve Nielsen quit the organisation in December after less than a year in his role. His departure followed that of Deborah Mayer, the head of the FIA commission for women.
In January, leading engineer Tim Goss left his role as single-seater technical director. He is now at Red Bull’s RB team.
And in May Natalie Robyn left her role as chief executive officer, external after just 18 months in the position.
Wittich’s departure comes weeks after a major controversy over the FIA’s racing guidelines broke out within F1, following a battle between title contenders Max Verstappen and Lando Norris at the US Grand Prix.
At the subsequent race in Mexico, the FIA agreed with the drivers that they would revise the guidelines with the aim of preventing a form of defence that has been perfected by Verstappen and is permitted by the current rules.
It is not clear whether Wittich’s departure is related to that scenario.
His predecessor Masi left the FIA after his role in the controversy at the Abu Dhabi Grand Prix in 2021.
Masi ignored the rules during a late safety-car period in that race and decisions led to Lewis Hamilton, who had been on course to win an eighth world title by winning the race, being overtaken by Max Verstappen, making the Dutchman champion instead.
Wittich has been less overtly controversial in his role, but there has remained an underlying discontent within teams and drivers about the management of FIA race control.