Charlie Whiting, Formula One's long-serving race director, has died on the eve of the 2019 season.
The 66-year-old suffered a pulmonary embolism in Melbourne where he was due to officiate the curtain-raiser of the new season.
FIA president Jean Todt led the tributes to the former chief engineer, saying he "embodied the ethics and spirit of this fantastic sport".
Whiting's entry into Formula One came as part of the Hesketh Racing team in 1977, but it was through his work at Brabham that he made his name.
As chief mechanic for the outfit owned by Bernie Ecclestone, he played an integral role in the championships won by Nelson Piquet in 1981 and 1983.
After leaving Brabham in 1988, Whiting moved on to serve as FIA technical delegate and then became FIA director and safety delegate from 1997.
Within this role, he was responsible for starting races as well as being the man teams would speak to about a variety of matters over the race weekend.
Todt said: "It is with immense sadness that I learned of Charlie's sudden passing.
"I have known Charlie Whiting for many years and he has been a great Race Director, a central and inimitable figure in Formula One who embodied the ethics and spirit of this fantastic sport.
"Formula 1 has lost a faithful friend and a charismatic ambassador in Charlie.
"All my thoughts, those of the FIA and entire motor sport community go out to his family, friends, and all Formula One lovers."
Meanwhile, Ross Brawn, Formula 1 managing director of motorsports, said he was "devastated".
He added: "I have known Charlie for all of my racing life. We worked as mechanics together, became friends and spent so much time together at race tracks across the world.
"I was filled with immense sadness when I heard the tragic news. It is a great loss not only for me personally but also the entire Formula 1 family, the FIA and motorsport as a whole. All our thoughts go out to his family."
Other figures from the sport have also paid tribute.