John Button, the father of 2009 F1 title winner Jenson, has died of a suspected heart attack.
Button Sr, who enjoyed a successful racing career of his own in Rallycross during the 1970's, passed away at his home in France on Sunday.
He was 70-years-old.
"Whilst we await confirmation, initial signs would indicate a suspected heart attack,” a statement from Button's management said. “A close friend who was visiting John on Sunday was the first to discover the tragic news.
"John's children Jenson, Natasha, Samantha and Tanya and the rest of the family are clearly devastated and ask for their privacy to be respected during this extremely difficult time."
John Button was a well-known figure in the F1 paddock, having attended the majority of races since his son made his debut with Williams back in 2000.
The crowning glory came in 2009 when Button took the championship title with Brawn GP before moving to McLaren the following season, with team boss Martin Whitmarsh one of the first to pay tribute.
"In my long Formula 1 career, I've encountered many drivers' fathers, but I think it's safe to say that John was perhaps more devoted to his son than any of them, he said. “Ever since Jenson was a boy, racing go-karts, his dad has been at his side, helping him, supporting him, finding the money for the next race.
"As Jenson grew older, and continued to win in cars, still John was always there, his most steadfast helper and supporter.
"And, even now, in recent years, during which Jenson has become the consummate Formula 1 world champion that he is, the most experienced driver on the Formula 1 grid in fact, still John has been ever-present, as loyal and as loving as ever, a benign and popular member of Jenson's small and intimate entourage.
"This coming season will be Jenson's fifth as a McLaren driver. I believe John has attended every grand prix over the past four seasons, and over that period he's become a unique and, I think it's fair to say, irreplaceable part of the McLaren 'family'.
"He was not only a great dad, but also a lovely man, and he'll be enormously missed by Jenson, of course, by all at McLaren, and indeed by the Formula 1 community at large.
"I'm sure that everyone at McLaren, and indeed everyone in Formula 1, will join me in sending our heartfelt condolences to Jenson, to the Button family, and to their many friends."
All at Crash.net send our condolences to the Button family.