Former Italian cycling champion and one-time Olympic silver medallist Davide Rebellin has died after a hit-and-run collision involving him and a truck near his home in the Venice region, local media reported on Wednesday.

The 51-year-old is regarded as one of the finest classics racers of his generation, Rebellin won seven of cycling's major one-day races.

In 2004, he was the first rider to sweep the Ardennes Classics treble of Liege-Bastogne-Liege, Flèche Wallonne and Amstel Gold.

He also won the Flèche in 2007 and 2009 as well as classics in San Sebastian and Zurich, both in 1997.

There were also stage race triumphs in 2001 and 2007 as he won the prestigious Tirreno-Adriatico and the Paris-Nice.

He took part in 19 Grand Tours including 12 Giro d'Italia, where he won his sole major tour stage and wore the overall leader's pink jersey for six days in 1996.

"This is an infinitely sad day for all those in cycling," Tour de France chief Christian Prudhomme said.

Rebellin was stripped of his Olympic road race silver medal from the 2008 Beijing Games after returning a positive test for the blood-booster EPO Cera.

"This is a victory for clean cycling," Rebellin had insisted after taking the silver. He always denied the offence.

Rebellin's positive, in both samples, came months after the end of the Beijing Games, during a re-testing campaign.

Lotto-Soudal general manager John Lelangue said Wednesday he was stupefied by the news of the rider's death.

"I just can't believe it. He was with us Sunday night at the Monte Carlo Criterium dinner," he said.

FDJ chief Marc Madiot compared Rebellin to a choirboy.

"He was a really nice guy. Polite, reserved, never a word out of place, he lived like a monk or a choirboy," said Madiot, who managed him in the late 90s.

"Once, after a training camp, we had a bit of a party that got out of hand, but he didn't even have a single drink."

Seven-time Tour de France King of the Mountains Richard Virenque also remembered him.

"He was a lovely, loyal person and we shared some wonderful moments together," said Virenque.

Italian media reported his death Wednesday saying he was killed instantly at a roundabout in a collision with a truck that left the scene without stopping.

Rebellin raced on until last year in the lower divisions and is remembered by his family as someone "who lived to ride his bike".