Gloucestershire Police is warning cyclists visiting the Forest of Dean to be vigilant following a spate of bike thefts.
Officers have received five reports of high-end bicycles being stolen throughout August.
Police say that thieves have been targeting holiday sites in Lydney and Coleford overnight and are cutting through locks or breaking into vans to take the electric bikes.
The most recent theft happened when a holidaymaker in Coleford was awoken to the sound of his van being broken into. A Santa Cruz Megatower mountain bike worth £8,000 was stolen from inside the vehicle.
Officers are now advising visitors to be extra vigilant and to report any suspicious activity immediately to police.
Inspector Nick Cook said: “We are proud that the Forest attracts so many visitors and holidaymakers, with many wanting to make use of the numerous bike trails.
“However, people still need to be vigilant, even if they are on a holiday park, as thieves will be opportunistic and can strike anywhere.
“We’re advising people to keep their bike safe and to make sure they use D-locks and to give their property the best protection.”
Gloucestershire Police has issued a range of advice on protecting bikes from thieves including double locking with two types of lock, securing the frame and wheels to a stand and taking easily removable parts off the bike such as wheels, lights, baskets and saddles.
Additional measures include parking in well-lit environments, registering the frame on a national database, marking the bike and asking for proof of ownership if purchasing second hand.
If your bike is stolen, contact police as soon as possible by calling 101 or reporting it online.
Anyone who has been the victim of a bike theft but hasn’t yet reported this can do so by completing an online form.