Italian cyclist Michele Scarponi has died after being hit by a truck during a training ride.
The 37-year-old was involved in a collision with a heavy goods vehicle near his home in the Le Marche region of Italy on Saturday morning.
Scarponi had recently been named Team Astana leader for the upcoming Giro d'Italia following a knee injury to Fabio Aru.
The veteran won the 2011 Giro after Alberto Contador was stripped of the title and claimed three stage victories in the race over the course of his career.
He had only just returned home after completing the Tour of the Alps on Friday when the accident occurred. Gazzetta dello Sport say he died instantly.
A statement from Team Astana read: 'This is a tragedy too big to be written.
'We left a great champion and a special guy, always smiling in every situation, he was a real milestone and a landmark for everyone in the Astana Pro Team.
'The Astana Pro Team clings to the Michele family in this incredibly painful moment of sorrow and mourning.'
Scarponi had been riding professionally since 2002 and was known on the tour as a prolific climber.
He was well liked by his colleagues and prolific on social media, where he often shared images of his training rides with a blue and yellow parrot named Frankie.
His penultimate post on Twitter showed him with his two sons.
He leaves behind his wife Anna and their twins, James and Thomas.
Scarponi's peers were quick to pay tribute to their friend as news spread around the cycling community on Saturday.
Vincenzo Nibali wrote on social media: 'I have no words, my friend.'
Contador said he was 'paralysed by the news' and 'speechless' as he remembered 'a great person with a contagious smile'.
Alejandro Valverde called Scarponi 'a great cyclist', while FCI president Renato Di Rocco described him as 'a model professional, a team player in every sense.'
Di Rocco invited cyclists participating in races across the world to stop for a minute's silence in Scarponi's memory, in a statement on the FCI's website.