Tour de France winner Floyd Landis has pulled out of Thursday's Jyske Bank Grand Prix in Denmark, race organisers said.
Danish race officials said they had worked hard to track down the American Phonak rider without success.
"Today, Phonak Danmark confirmed the cancellation. They could not say anything about why Landis has disappeared," race press officer Nils Finderup said.
"We have tried to call him, to call his agent, and to call the head of the Phonak team, but no one has answered."
On Wednesday Landis cancelled his planned start in the Acht van Chaam street race in the Netherlands.
Dutch news agency ANP quoted his team mate Koos Moerenhout as saying that Landis had pain from hip problem and had gone gone to see his doctor in Germany.
Landis completed his first Tour de France victory in Paris on Sunday.
