Photo from Chiara Marra on Flickr
The jersey had been donated by the Italian cycling museum in Madonna del Ghisallo for display at Milan's bike and motorbike fair. They have appealed for a swift return.
Pantani, known as "the pirate" because of his swashbuckling style of racing and the colourful bandana he wore to cover his shaven head, was one of Italy's most popular sportsmen, the Reuters report said. The last man to win the Giro d'Italia and Tour in the same year, Pantani died of a cocaine overdose in February 2004 at age 34.