Children as young as 13 are using Snapchat to buy vape liquid - unaware dealers have laced it with the dangerous synthetic drug spice, a BBC investigation has found.

Our reporter, posing as a schoolgirl, bought four bottles through a dealer on the social media site that later tested positive for the so-called zombie drug.

Teenagers have described horrendous withdrawal symptoms after vaping it, while one parent said she feared finding her daughter dead in her bed.

A Snapchat spokesperson said using the site to buy and sell vapes or illegal drugs was strictly against rules and that it proactively shut down dealers' accounts.

New research from the University of Bath has warned of a growing threat to young people unknowingly ingesting spice, and found in one area more than a quarter of schoolchildren's confiscated vapes tested positive for the substance.