The 2006 MotoGP champion, Nicky Hayden has died from injuries sustained when he was hit by a car while cycling in Italy last Wednesday.
Hayden was riding near Rimini when the accident occured.
He was subsequently rushed to a local hospital with severe head and chest trauma and several fractures, before being transferred to the Bufalini Hospital in Cesena.
The 35-year-old's condition was not stable enough to perform surgery to relieve the pressure on his skull caused by cerebral edema.
He remained in a critical condition in intensive care through the weekend.
A statement from the hospital said Hayden died on Monday.
"On behalf of the whole Hayden family and Nicky's fiance Jackie I would like to thank everyone for their messages of support - it has been a great comfort to us all knowing that Nicky has touched so many people's lives in such a positive way," his brother Tommy Hayden said.
"Although this is obviously a sad time, we would like everyone to remember Nicky at his happiest - riding a motorcycle.
"He dreamed as a kid of being a pro rider and not only achieved that but also managed to reach the pinnacle of his chosen sport in becoming world champion. We are all so proud of that.
"Apart from these 'public' memories, we will also have many great and happy memories of Nicky at home in Kentucky, in the heart of the family. We will all miss him terribly.
"It is also important for us to thank all the hospital staff for their incredible support - they have been very kind.
"With the further support of the authorities in the coming days we hope to have Nicky home soon."
Hayden made 217 MotoGP starts between 2003 and '16, beating Valentino Rossi to the 2006 world championship in the fourth of his six seasons with the factory Honda team.
He moved to Ducati in 2009 and, later, the Aspar team, before racing his last full season in MotoGP™ in 2015. He was then inducted into the MotoGP™ World Championship Hall of Fame at the season finale in Valencia.
The next challenge for the ‘Kentucky Kid’ was WorldSBK, where Hayden took a number of podiums and his first win in the class in his rookie year, besting difficult conditions at Sepang to join another exclusive club as he became a winner in both MotoGP™ and WorldSBK. The American also became the first MotoGP legend to return to Grand Prix racing in 2016, as a replacement rider at Aragon and Phillip Island.
Hayden raced his last laps for Red Bull Honda World Superbike team at Imola, in Italy, on May 14th.