MADRID: An international law enforcement operation targeting a sophisticated underground banking network allegedly used by organised crime groups to finance major drug trafficking operations has resulted in the arrest of 21 suspects and the seizure or freezing of assets worth approximately €20 million.

The investigation, led by the Spanish National Police and supported by Europol, focused on an international financial network known as the “Dubai Bank”, which investigators believe provided underground banking services to criminal organisations involved in drug trafficking and money laundering.

The network is suspected of making large sums of money available to criminal groups in different countries within a short period, providing the financial infrastructure needed to fund major cocaine shipments and move criminal proceeds.

A major enforcement action in Spain on 22 July 2026 resulted in 15 arrests. Spanish authorities also issued 19 international arrest warrants for suspects located outside the country.

Six of those warrants have since been executed, resulting in four arrests in the United Arab Emirates, one in Egypt and one in the Netherlands.

Among those detained was a leading figure in the underground banking network, whom Europol had identified as a High Value Target. The suspect is believed to have played a key role in providing financial services for major drug trafficking operations around the world.

Millions in Assets Seized

Authorities have identified, seized or frozen assets with an estimated value of €20 million.

The assets include 48 properties worth more than €14 million, high-end vehicles valued at over €1.6 million and 121 bank accounts containing approximately €2.3 million.

Investigators also identified assets allegedly acquired using illicit funds, including a luxury property in Ibiza.

The investigation revealed a sophisticated system designed to move value between jurisdictions without necessarily physically transporting cash across borders.

Instead, underground banking networks can rely on brokers and internal accounting mechanisms to settle transactions between countries.

These mechanisms can involve trade transactions, companies and their bank accounts, cash pooling, or transfers involving other assets.

The network allegedly operated on a commission basis, with fees varying according to the transaction and other circumstances.

Banknote Serial Numbers Used as Tokens

Investigators also uncovered an unusual system used to authenticate certain cash transactions.

A unique identifier — frequently the serial number of a banknote — could be passed through the transfer chain.

When the recipient collected the cash, presenting the matching identifier allowed those involved to verify that the money was being handed to the intended person.

According to investigators, such mechanisms formed part of the broader financial infrastructure used to move criminal funds internationally while limiting the need for conventional cross-border cash transfers.

Cocaine Shipment Led Investigators to Financial Network

The investigation, known as Operation DRAKKAR, originated from a major cocaine trafficking case in February 2021.

Spanish National Police officers intercepted a vessel in waters off the Spanish coast and discovered 1,835 kilograms of cocaine.

All nine crew members were arrested. After the crew and drugs were removed, the vessel was towed to the port of Gijón in northern Spain.

The investigation took an unexpected turn when the vessel subsequently sank after taking on water through a leak allegedly caused by its captain.

Investigators later discovered that the vessel had been carrying another 1,650 kilograms of cocaine, which had been concealed on board.

Members of the criminal network are suspected of subsequently entering the sunken vessel and recovering the hidden shipment.

Investigators established that both cocaine consignments had been loaded in South America in January 2021.

The plan was allegedly to transfer the drugs at sea to high-speed boats, which would then transport the cocaine ashore in Spain.

Following the Money

The investigation into the people behind the cocaine shipment eventually led authorities further up the criminal chain.

Investigators established links to other suspected drug trafficking operations in different parts of the world.

Following the financial trail then exposed individuals suspected of financing drug shipments and laundering the resulting criminal proceeds.

This ultimately led investigators to the underground banking infrastructure allegedly used to support organised crime.

Europol said the network demonstrated how criminal organisations can rely on specialised financial brokers and alternative value-transfer systems to move and conceal illicit funds internationally.

Europol Supports International Investigation

Europol has supported the investigation since October 2024 through an Operational Taskforce established to assist Spanish authorities.

The agency facilitated international information exchange and provided operational and financial analysis that helped investigators identify key money brokers within the network.

Europol specialists also provided expertise in underground banking, asset tracing and asset recovery.

During the Spanish action day, a money-laundering specialist was deployed to support investigators on the ground from a mobile office.

Given the international reach of the suspected network, cooperation between law enforcement agencies in multiple countries was central to the investigation.

Authorities from the Netherlands, Sweden and the United States also contributed, including the US Drug Enforcement Administration (DEA).

The arrests and asset seizures represent a major financial blow against an underground banking infrastructure suspected of supporting drug trafficking on an international scale.

The investigation also highlights the growing importance of financial intelligence in tackling organised crime, with authorities increasingly targeting not only the drugs and traffickers themselves but also the financial networks that enable criminal organisations to operate across borders.

Source — Europol