Geraint Thomas’ Tour de France trophy was stolen from the Cycle Show at the NEC in Birmingham.
Team Sky loaned the trophy to Pinarello for the show in September, where it was displayed alongside the other Grand Tour trophies, Vuelta de Espana and Giro d’Italia.
A statement on Team Sky’s website said: "Regrettably, during the clear-up operation at the end of the event, Geraint Thomas’s Tour de France trophy was momentarily left unattended and stolen.
"The matter is obviously now subject to a police investigation.
"In the meantime, Team Sky is liaising with all relevant parties to agree on the best course of action to resolve the issue."
Richard Hemington, managing director of Pinarello (UK) said: "We are obviously devastated about this.
"We accept full responsibility and have personally apologised to Geraint.
"Obviously we all hope that the trophy can be recovered.”
Thomas said: "It is incredibly unfortunate that this has happened.
"It goes without saying that the trophy is of pretty limited value to whoever took it, but means a lot to me and to the team.
"Hopefully whoever took it will have the good grace to return it.
"A trophy is important, but clearly what matters most are the amazing memories from this incredible summer – and no-one can ever take those away."