Tourists have been warned not to leave drinks or food unattended as criminals in Colombia use drugs to subdue their victims.
The British Embassy said it had received reports of drugs being used to make victims disorientated and vulnerable.
The Foreign Office said this included the use of scopolamine, which temporarily incapacitates unsuspecting victims.
The advice was updated to say: "Drugs can be administered through food, drinks, cigarettes, aerosols and even paper flyers.
"Victims become disoriented quickly and are vulnerable to robbery, sexual assault and other crimes. Avoid leaving food or drinks unattended and don’t take anything from strangers."
