Inside Mexico's Infamous Meth 'Super Labs'

In the central mountains of Mexico lies the city of Culiacan. By rights it should be a sleepy backwater, a one-donkey rural nowheresville, but it is not.

Alongside manicured parks and pristine government buildings it boasts shopping malls, designer clothes shops, five star hotels, shi-shi restaurants and nightclubs.

What makes Culiacan so different to other rural cities is that it is the home of one of the country's most powerful and ruthless gangs, the Sinaloa Cartel. Where there are cartels, there is money - lots of it.

The Sinaloa deal exclusively in drugs, vast quantities of them.

It's a multi-million dollar business that takes place under the nose of the country's anti-narcotics units which patrol the ganglands of the city day and night.

In recent years the profitability of their business has soared.

The reasons are twofold, firstly they are focusing on the production and export of methamphetamine or crystal meth, rather than cocaine and heroin, and secondly they have developed ways to produce the drug on an industrial scale.

The cartels generally, but the Sinaloa obsessively, maintain incredibly high levels of security. It's why they have lasted and indeed thrived for so long.

After eight months of negotiation they agreed to allow us to see their meth production process and with it see a 'super lab' at work. It has never been allowed before.

Inside a heavily-guarded factory, men in overalls and wearing gloves and face masks mix together a series of chemicals into huge drums.

There is an instant reaction, sending clouds of foul smelling, toxic and highly explosive gas into the air.

They barely speak to avoid identification and they are wary of the chemicals.

They move back and forth as the ingredients react. The reaction process only takes 15 minutes or so but to get to the point where they have created the meth will take a few days.

The reason why meth is so popular with the cartels is that it is completely synthetic and can be made cheaply at home.

The cartels control ports that allow them to bring in some of the most important ingredients in bulk from India and China. Their distribution network to markets in the United States, Europe and further afield have been in place for years.

But the ability to produce huge amounts of the drug marked something of a 'narco revolution' for the Mexican cartels.

They were so confident of the purity and quality of their meth that initially they used to include batches of the "product" with cocaine and marijuana shipments that had already been ordered - they sent it for free.

They were convinced the foreigners would be hooked; they were right.

The production of the drug is one aspect of the process but making money from it means preparation, packing and shipping.

The 'super lab' is made up of a number of different locations.

We crossed town to another secret building where we found 10 men in masks and gloves sitting around tables laden with crystal meth.

For the next 48 hours they will pack the powder into tiny capsules before it is shipped abroad.

There is a quarter of a million pounds-worth of drugs on the table and the gang leader told me he can produce that amount once a week.

"We are making £12m a year profit and we are a medium-sized operation," he told me.

"It all goes to the US because it sells for more, the product goes directly to the United States," he said, adding that the value of the drugs increases nine times by the time they get to Europe.

"The majority of it is taken in trailers - that's how they take it from here," he said.

This huge, highly-organised business is not actually about making drugs, it is quite simply about making money.

Most experts who study the cartels believe it is unlikely that given their reach across society they will ever be beaten, well not any time soon.

"They become a form of an alternative justice system or alternative police and that is very worrying for the country," Mexico-based British journalist and author Ioan Grillo told me.

"And that leads you to understand how the conflict has led to more than 84,000 cartel-related murders in the last seven years.

"Corruption is extremely bad to the point where you have police officers who are not simply turning a blind eye to organised crime, they're full on assassins for organised crime, they are full on cartel members," he said.

The Mexican authorities and the United States drug enforcement agencies are struggling to even remotely control the trafficking of drugs across Mexico's borders.

Like a multinational company it is driven by the market. For now the demand is high. So the supply keeps coming.

:: Watch our Special Report ‘Narco State: Inside Mexico’s Drug Cartels’ on Sky News at 9.30pm on Friday, or on Sky News Catch Up, skynews.com and mobile apps from today.