Williams chief technical officer Paddy Lowe has taken a "leave of absence" from the team with little more than a week until the opening race of the 2019 season.
The team missed the opening two and a half days of testing for the 2019 season due to the late completion of the vehicle, with deputy team principal Claire Williams describing the delay as "embarrassing".
Last year's Williams was the first designed by Lowe, but their season was challenging with aerodynamic problems on the auto, which led to them finishing tenth overall - Williams' worst in their history in the sport.
It ostensibly leaves Williams without a technical director just eight days before the opening Grand Prix of the season gets underway in Australia.
The team conducted a major review into its processes over the 2018 season to ensure its '19 auto did not suffer from the same problems.
A team spokesperson confirmed to Autosport that Lowe "is taking a leave of absence from the business for personal reasons".
Williams' slow start, plus on-track performance in testing, led to speculation over Lowe's immediate future at the team.
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