[Iceman]

Newly-crowned champion Casey Stoner admitted immediately after the crash he had feared for Simoncelli.

"As soon as I saw the footage it just makes you sick inside," the Australian told BBC2.

"Whenever the helmet comes off that's not a good sign."

Tributes poured in for Simoncelli from teams and riders.

British MotoGP rider Cal Crutchlow wrote on Twitter: "RIP Marco Simoncelli ! A great rider and all round nice guy. My thoughts are with all his family & friends. I will never forget today."

Formula One driver Mark Webber tweeted: "R.I.P Marco A special talent that will be missed... Thinking of your loved ones, and all the motogp paddock..mark."

A message on Simoncelli's Gresini Honda team website read simply "CIAO 'SUPER SIC'.

The Rizla Suzuki team wrote: "All at Rizla Suzuki are deeply affected by today's tragic events and send their deepest condolences to Marco's family and friends during this time of great loss.

"R.I.P Marco Simoncelli, 20 January 1987 - 23 October 2011 - A true competitor."