The man is accused of laundering more than €200 million for criminal organisations.
Spanish police have arrested one of Europe's most wanted suspects for money laundering, Europol has said.
The Irish-British dual national was detained on Monday in the southern city of Malaga after a months-long operation.
The man is accused of laundering more than €200 million in illicit money for worldwide criminal organisations.
The money was allegedly transferred using the hawala underground banking system, which does not record any physical monetary transaction.
Authorities began investigating in early 2021 after Spanish authorities seized 200 kilograms of cocaine and €500,000 in cash, which was found hidden in the secret compartments of a number of vehicles.
Two other people were also arrested in Spain and one in the UK while 11 properties were searched, Europol said in a statement. One of the suspects ran a car dealership that allegedly provided vehicles to criminal organisations.
"The main suspect and his associates were in charge of collecting large amounts of cash from criminal organisations which they would then ‘deliver’ to other criminal organisations in other countries," the agency said.
A source close to the investigation told AFP that the main suspect was 62-year-old John Francis Morrissey. Europol has not confirmed his identity.
The agency did state the man has known links to the international cartel of alleged Irish organised crime boss Daniel Kinahan, which has been sanctioned by the US.
"In April of this year, this person and his company were designated by the US Department of the Treasury for providing support to the Kinahan clan," Europol stated.
"The main suspect was considered a high-value target by Europol for his involvement in a number of high-profile criminal cases throughout Europe."
The 18-month investigation was led by Spain's Guardia Civil, alongside the UK's National Crime Agency, Dutch police and the Irish Garda.