Two Ducati motorbikes, raced by two of the finest exponents of the craft, are coming to auction in Monaco on May 11 and 12.

Built in December 2009, 2007 Moto GP champion Casey Stoner's Ducati Desmosedici GP10 "CS1" was track tested by the Australian rider in Sepang, Malaysia in February 2010.

Stoner first competed with the bike in Qatar in April 2010 and achieved his first race victory with it at the Australian GP at Phillip Island in October 2010.

Stoner enjoyed pole positions in Qatar, Phillip Island and Valencia on board the "CS1" and achieved podium positions in Valencia, Assen and Catalunya.

Six-time Moto GP world champion Valentino Rossi's Ducati Desmosedici GP11 "VR2" was likewise built at the Ducati factory, in December 2010. Rossi first competed with the machine in the Qatar Grand Prix in March 2011.

In what was a poor season by his standards, Rossi recorded a solitary podium position with it at Le Mans, France in May 2011.

Valentino Rossi on board his Ducati during testing in Sepang

"The release of two very special machines like these is an extremely rare occasion for us, so the lucky buyer must not only enter into a confidentiality agreement, but also become a close member of the 'Ducati family'," said Ducati's technical director, Filippo Preziosi.

"The Desmosedici GP10 and GP11 were two very interesting bikes in our GP project history and therefore will represent exciting opportunities for serious collectors."

No estimates have been provided for the machines as yet.

Petrol heads may also be interested in this signed photo of Sebastian Vettel, which is currently available through Paul Fraser Collectibles.