The owners of a Somerset visitors' attraction are offering a £500 reward after a full-size Dalek was stolen.
Police believe the Dalek may have been stolen to order
The 5ft model, believed to be an original from the cult BBC Dr Who series, was taken from Wookey Hole Caves near Wells overnight on Monday.
Bosses say it is worth thousands of pounds and promise to pay the reward for its safe return "or capture".
A spokesman said: "There may be a black market out there for Daleks - but it's still a strange thing to steal."
The Dalek had been on display at the Bath and West Show and was in temporary storage at the Wookey Hole site when it was taken.
It was due to be used to promote a Doctor Who theme weekend at the caves later this month.
Avon and Somerset Police believe a vehicle may have been used to move the model of the Doctor's nemesis.
Pc Neil Wolsteholme said: "The Dalek could have been stolen to order or somebody could have taken it as a joke.
"It is obviously quite distinctive and somebody must know where it is."
He added: "It is fair to say this is the most unusual theft I have been involved in investigating."