The police van sits ominously in front of us. All eyes are fixed on the vehicle, watching apprehensively for any signs of movement. Despite the bright sunshine outside, I can't risk leaving our car, which is parked on a secluded lay-by on the outskirts of London. The stakeout is as tense as I imagined.
Just as I start to twitch uncomfortably in my seat, a white delivery van rolls past and the police roar into life. We follow in hot pursuit. Our quarry turns off the road and stops, allowing time for uniformed officers to bundle out and surround the unsuspecting postal workers. The two men look stunned in their high-vis jackets as they are questioned and searched by the side of the road.
While Indian drugs like these are considered relatively safe, the proportion of active ingredients in imported Chinese pharmaceuticals can vary wildly, Mr Lee-Frost explains. "It's like baking a very badly-made cake, with all the ingredients at one end and filler at the other," he says. "You can end up taking tablets that are all filler, or tablets that are all active."
Ending demand
With around 50 operations involving arrest warrants taking place each year, the MHRA is so busy that it's starting to run out of code names for its investigations. "We've been through boy's names, girl's names, US presidents and now we're onto breeds of dog," says Mr Lee-Frost.
But despite the high level of enforcement action, it will never be effective unless they can raise public awareness, he says. "The internet is like the wild west: you can buy anything there. The way to tackle this is to tackle demand. If we can alert people to the dangers of buying things online then that's half way to getting the job done," he says. Only by fighting on both fronts can the MHRA hope to win the war against unlicensed medicines.