Former Formula 1 driver Alex Zanardi is in a “critical condition” after requiring surgery on a head injury sustained in an accident during a handbike relay in his native Italy.
The 53-year-old was involved in a crash with a lorry in Pienza on Friday.
Zanardi was taken by helicopter to hospital in Siena, where he is on a ventilator in intensive care and “the neurological picture remains serious”.
His “neurosurgical and maxillo-facial” operation lasted almost three hours.
Zanardi had both legs amputated after crashing in the American Memorial 500 Cart race at Lausitz, Germany, in 2001.
He has since become a four-time Paralympic handcycling gold medallist.
“You have never given up and with your extraordinary fortitude you have overcome a thousand difficulties,” said Italian prime minister Giuseppe Conte on Twitter.
“Come on Alex Zanardi, don’t give up. All of Italy is fighting with you.”
Former Formula 1 world champion Mario Andretti tweeted: “I am so anxious and frightened about Alex Zanardi that I’m holding my breath. I am his fan. I am his friend.
“Please do what I’m doing and pray, pray for for this wonderful man.”
Zanardi was taking part in an event called the Obiettivo Tricolore, a journey that sees the participants riding across Italy on handbikes, cycles or wheelchairs.