According to Trading Standards, illicit or non-compliant vapes can be anything with tank sizes greater than 2ml, a nicotine strength of more than 20ml or labels that do not display manufacturer details and health warnings.
The Medicines and Healthcare Products Regulatory Agency strongly advises consumers not to use them as the true content - and any possible health risk - is unknown.
On the road, Paul and Connor quickly find a stash of between 12 and 20 packs of illegal vapes at the back of a shop counter.
"It would be unusual to have so few in a shop that sells quite frequently like this, so it's just a case of where they're hiding the rest," says Paul.
We head to a room at the back of the shop. There is a stench of urine. It is full of litter and we are deep in seemingly empty cardboard boxes.
Paul's hunch is proven right though as a search among the rubbish unearths a box of illegal vapes.