Doctors have issued a fresh warning that toddlers are at risk from e-cigarette nicotine refills, saying even a few drops could make a child very sick.

Some media reports of children ingesting the liquid are the latest to underline “the risk posed by nicotine liquid to children”, said the experts, who called for “public education and legislation to improve the safety profile of e-liquid containers.”

In April, the US Centers for Disease Control and Prevention (CDC) reported a surge in calls to poison centres after people accidentally swallowed or inhaled nicotine from a refill cartridge, or spilled it on their skin or in their eyes.

The CDC said there was no legal requirement for the liquids to be packaged in child-proof containers, and they came in sweet and fruit flavours “that are appealing to children.”