Charlie is trained to sniff out drugs

Twelve of them have been either cautioned or charged.

British Transport Police say drugs worth tens of thousands of pounds pass through the station every year.

Officers use a special sniffer dog called Charlie.

Supplying drugs

Charlie is trained to circle anyone carrying drugs while officers move in to detain the suspect.

In the past year, Charlie has made 70 visits to Leeds station and sniffed out 350 people carrying drugs.

This has resulted in 67 people being charged with supplying drugs.

PC John Mann of the British Transport Police said: "We get a lot of people carrying drugs for personal use.

"But we have had major drug dealers stopped by the dog."