Nakajima joins a team that refused to employ his father

The 21-year-old, a member of the driver development programme of Williams' new engine partner Toyota, raced in the Formula Three Euroseries this year.

Nakajima will work with fellow test driver Narain Karthikeyan and race drivers Nico Rosberg and Alexander Wurz during Williams' winter test programme.

Satoru Nakajima raced in F1 from 1987-91 with Lotus and Tyrrell.

A protege of Toyota's arch-rivals Honda, the older Nakajima made his debut as team-mate to the late Ayrton Senna at Lotus-Honda.

It was partly Williams' refusal to accept Nakajima as a race driver that led to them losing Honda engines at the end of the 1987, bringing to a close a two-year period of domination of F1.