How does Switzerland keep the grim realities of gold mining under wraps? Gold, the enduring safe investment and symbol of wealth, comes at a high price.

Mined in slave-like conditions, it has been linked to everything from funding civil wars in Africa to causing environmental disasters in Latin America.

The market for gold is enormous with 70% of global production handled by just one country: Switzerland.

The industry has been protected by the Swiss state for more than a century, and turning a blind eye here is standard practice.

Despite attempts at reforms, a lack of transparency still remains. We travel to Peru, Congo, Dubai and Switzerland to investigate.