Illegal cigarettes: How sniffer dogs uncover illicit trade
1 December 2016 Last updated at 20:58 GMT
A BBC investigation has tracked how hundreds of millions of cigarettes made in one factory in Eastern Europe are being smuggled into the UK and sold illegally across the country.
Smugglers buy the packs in Belarus for as little as 40p each then transport them to Britain using secret hiding places in cars and lorries.
This film shows the lengths some traders go to to conceal their trade in illicit cigarettes.