Welcome to assignment on the BBC World Service. I'm Danny Vincent and this week I'm

trying to find out why despite a recent ban by the UK government legal hires are still available on Britain streets.

I smoked a hand on his box, clockbur corringe, I've smoked annihilation, smoke chronic and a few others.

Psychoactive substances like these represent a new frontier in the battle against illegal drugs. low cost, high profit and readily available on the internet.

Where are they being manufactured?

I'm going to for a meeting with drug traffickers. I'm being taken a short distance to meet

a Mr. Wong, the boss of a chemical company, but this is far from a legitimate deal.

I'm posing as a British importer wanting to bring illegal drugs into the country.

So this is Shudaj Wang, right? So this is where your bosses?

Okay. So just going in now?

Is that off to you?

I'm being taken into a private dining room in a cafe.

I'm being shown a huge array of drugs laid out on the table.

So you've got three bags of different products,

and one is a crystal structure, and Mr. Wong is taking out other products here.

The press is 1,200 but customers always buy this one because this one is more stronger.

And have you sent this to England before?

Yeah, no problem.

My journey begins in the English city of Lincoln, in the east of England, a city that has one of the worst drug problems in the country. Drugs like spice and mamba, which mimic the effects of traditional substances like

cannabis, can easily be found here.

This despite a new law banning the importation and sale of the drugs coming into effect in May this year.

I'm walking through Lincoln City Centre. There have been more than 800 incidents relating to so-called

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