Intergovernmental organisation the Organisation for Economic Cooperation and Development (OECD) has released a new report exposing how gold concentrate – semi-processed gold that moves quietly through the maritime system – has become one of the most vulnerable and least scrutinised channels for gold laundering and illicit financial flows.

While most public attention focuses on refined gold and doré bars, the report highlights that over 15% of global primary gold production is now shipped as concentrate, typically in bulk containers that receive minimal inspection.

As concentrate resembles ordinary mineral material and lacks public pricing benchmarks, criminal networks can misdeclare or under-invoice gold shipments with ease; hide illicitly mined gold by blending it with legal supplies; and move “phantom” shipments – empty containers declared as valuable concentrate – to launder money, the report indicates.

Key messages contained in the report include that the global trade in gold concentrates – unrefined gold in containerised bulk bags – is exposed to distinct vulnerabilities that can be exploited for gold laundering (concealing the origins of gold) and gold-based money laundering (using gold to launder the proceeds of crime).

The report points out that the profile of gold concentrate makes it vulnerable to trade‑based money laundering, because it is lightly tracked, poorly understood, difficult to price, shipped in bulk as an unremarkable material, passed through copper-dominated trading and processing circuits and can be easily misinvoiced or misdeclared without attracting the scrutiny applied to refined gold.

The amount by which declared imports for the relevant harmonised system code surpassed corresponding exports increased by 400% between 2020 and 2024, with the discrepancy in 2024 amounting to a third of all concentrates imports in value terms, according to the UN Comtrade.

The report highlights that significant volumes of gold concentrate are traded internationally and transported in maritime containers.

In 2024, over 15% of world primary gold production was shipped as concentrate, according to precious metals research consultancy Metals Focus.

While concentrate grade varies significantly, mined production of gold globally amounted to about $280-billion the same year, rising to over $400-billion this year owing to the surge in gold prices, the report outlines. Moreover, several key gold-producing countries have significantly increased exports of gold concentrate.

The beneficiation, blending and transformation stages of gold concentrate involve significant laundering risks, particularly in contexts where due diligence is weak or absent, the report warns.

Processing facilities that source material from multiple suppliers blend inputs in ways that, when accompanied by incomplete or falsified documentation, can obscure the origin of illicit gold, it points out.

The report underscores the importance of training and equipping law enforcement personnel to detect and analyse crime typologies linked to gold concentrates.

It also suggests that policymakers consider introducing stricter licensing and oversight of processing plants and smelters.

The report also stresses that all private-sector actors in the gold and copper supply chains – especially processing plants, traders, refiners and smelters – should conduct enhanced due diligence on gold concentrates in line with the OECD Due Diligence Guidance for Responsible Supply Chains of Minerals from Conflict-Affected and High-Risk Areas.