The Brazilian government has made several attempts to take control of logging in the Amazon. But despite high-profile crackdowns, the trade in illegal timber is vast and growing.

Pará state is the largest timber producer and exporter in the Brazilian Amazon. It is where a lot of the Amazon timber available in the UK comes from. Yet an estimated 78% of logging in Pará is illegal.

In neighbouring Mato Grosso, the second largest timber producer and exporter, 54% of logging is believed to be illegal. And the situation is the same in other states too. According to the former head of the Brazilian National Forest Service, 60% of logging in the Amazon is illegal.

The government tried to regulate the industry and stem the trade in illegal timber. But the systems it designed to keep an eye on the loggers have been corrupted. Instead of keeping illegal timber out of the marketplace, criminals are exploiting loopholes to create false paper trails.

Wrapped in this fake paperwork, it's almost impossible to tell legal and illegal timber apart.

The Brazilian environmental police, IBAMA, has been taking the fight to the sawmills at the heart of the racket. A successful raid gets headlines, and might seize a few truckloads of timber - but the problem is so much bigger than that.

IBAMA estimates that in Maranhão and Pará states alone almost 500,000 m³ of lumber had fraudulent documents last year - enough to fill 14,000 trucks.

Amidst this criminality, just one thing is crystal clear. When you buy timber from the Amazon, you're taking a massive risk - and the timber that you get may well be illegal.