A2 Milk's chief technical officer Phil Rybinski - appointed during the tenure of previous chief executive Jayne Hrdlicka - has left the company after just a year in the job.
Rybinski, who had previously worked for Dairy Farmers, Fonterra and Parmalat Australia, started at a2 Milk in January last year.
In a statement, a2 Milk said Rybinski was leaving to pursue other interests.
Shareef Khan, chief operations officer, will assume responsibility for all technical function activities on an interim basis while a replacement is found, a2 Milk said.
A2 Milk said Race Strauss had started as chief financial officer, as advised last year, after Craig Louttit chose to step back from the role.
Louttit would continue as deputy chief financial officer.
Strauss spent over 20 years at Unilever where he held a variety of senior roles.
In recent years, he had worked in chief financial officer roles for the Qantas Group, including at Jetstar and at Qantas Airlines.
Geoff Babidge, who is largely credited with turning the alternative milk company into today's multi billion dollar business, is back as chief executive and managing director in an interim arrangement Hrdlicka stepped down in early December following after just 18 months in the job.