Sir Frank Williams has been admitted to hospital, and is in a stable condition, the former Formula 1 team principal's family has confirmed.
Williams, 78, founded his racing team in junior single-seater categories in 1966, and became an F1 constructor in the late 1970s - his team winning its first Grand Prix at Silverstone in 1979. Under his patronage, Williams won seven drivers' and nine constructors' championships in a 50-year F1 career.
A statement from Williams's family said: "Sir Frank Williams has recently been admitted to hospital where he is currently in a stable condition.
"Frank's medical condition is a private matter and therefore the family will not be releasing any further details at this time. We ask for you to respect the family's privacy. The team will release a further update in due course. Thank you."
Williams suffered severe injuries in a road accident in France in 1986, which rendered him tetraplegic. But he continued to run the team in spite of his injuries and, along with co-founder Sir Patrick Head, Williams became a powerhouse team of the late 1980s and throughout the '90s. For his services to the sport, he was knighted in 1999.
Williams ended his association with the team that bears his name in September this year, soon after its acquisition by Dorilton Capital.