Christian Horner has been dismissed from his role as Red Bull Racing team principal.
The 51-year-old, who joined Red Bull in 2005, was the longest-serving team principal in Formula 1 having spent 20 years in the position.
Red Bull issued a statement, saying:
"We would like to thank Christian Horner for his exceptional work over the last 20 years. With his tireless commitment, experience, expertise and innovative thinking, he has been instrumental in establishing Red Bull Racing as one of the most successful and attractive teams in Formula 1.
"Thank you for everything, Christian, and you will forever remain an important part of our team history."
It added that with immediate effect, Laurent Mekies will take over the duties of CEO at Red Bull Racing. As part of his change, Alan Permane, currently Racing Director, will be promoted to Team Principal at Racing Bulls.
Red Bull sit fourth in the constructors' championship.

Sabalenka sees off Kasatkina to reach French Open fourth round
Parry stuns Anisimova to reach first Grand Slam fourth round at French Open
Osaka survives three-set scare against teenager Jovic
Cobolli cruises past Tien in straight sets to snap American's winning run
Liverpool sack Slot after underwhelming season