Brawn's deputy technical director Joerg Zander has left the team.
The German joined the outfit, when it was Honda, in July 2007, having had spells at BAR, Williams and BMW-Sauber.
Zander helped play a role in creating Brawn's successful BGP 001, which has won six of the first eight races of the season.
A Brawn GP spokeswoman confirmed Zander had left last Friday.
"Joerg contributed significantly to our success so far this season for which we thank him and wish him all the best for the future," she said.