Police units around the world have joined forces in a series of covert operations targeting one of West Africa’s most feared criminal networks - Black Axe.

Operation Jackal III saw officers in body armour carry out raids in 21 countries between April and July 2024.

The mission, co-ordinated by global policing agency Interpol, led to the arrest of 300 people with links to Black Axe and other affiliated groups.

Interpol called the operation a “major blow” to the Nigerian crime network, but warned that its international reach and technological sophistication mean it remains a global threat.

In one notorious example, Canadian authorities said they had busted a money-laundering scheme linked to Black Axe worth more than $5bn (£3.8bn) in 2017.

“They are very organised and very structured,” Tomonobu Kaya, a senior official at Interpol’s Financial Crime and Anti-Corruption Centre, told the BBC.

According to a 2022 report by Interpol, “Black Axe and similar groups are responsible for the majority of the world’s cyber-enabled financial fraud as well as many other serious crimes”.

Mr Kaya said innovations in money-transfer software and cryptocurrency have played into the hands of group, which are renowned for multi-million dollar online scams.

“These criminal syndicates are early adopters of new technologies… A lot of fintech developments make it really easy to illegally move money around the world,” he said.

Operation Jackal III was years in the making and led to the seizure of $3m of illegal assets and more than 700 bank accounts being frozen.

Many Black Axe members are university educated and are recruited during their schooling.

The organisation is a secretive criminal network with trafficking, prostitution and killing operations around the world.

Cyber-crime, targeting individuals and businesses, is the organisation's largest source of revenue.

Multiple so-called “Jackal” police operations have taken place since 2022.

Dozens of Black Axe and other gang members have been arrested and their electronic devices seized during these transnational raids. This work has enabled Interpol to create a vast intelligence database, which is now shared with officers throughout its 196 member countries.

“We need to have data and to collate our findings from these countries to help build a picture of their modus operandi,” said Mr Kaya.

Despite multiple international arrests, some experts feel not enough is being done to address the root of these crime syndicates in West Africa.

“The emphasis must actually be on prevention not on outright operations against these criminal groups,” said Dr Oluwole Ojewale, West Africa Regional Co-ordinator from the Institute for Security Studies.

Nigeria, which has witnessed widespread anti-corruption protests in recent weeks, is one of Africa’s largest economies, but has as many as 87 million people living below the poverty line, according to the World Bank. It is also the main recruitment ground for Black Axe.

Interpol said it was carrying out training exercises with key Nigerian stakeholders and police officials. But corruption, and allegations of collusion between Black Axe and local authorities, remain major obstacles.

“It is the politicians who are actually arming these boys,” said Dr Ojewale. “The general failure of governance in the country has made pressures for people to be initiated [into Black Axe].”

Despite its current global reach, Interpol’s Jackal Operations have their origins in Ireland.

Following a series of police raids by the Garda National Economic Crime Bureau (GNECB) in 2020, a handful of Black Axe members were arrested, paving the way for the exposure of a far wider network.

“They were very under the radar, very low-key,” said Michael Cryan, detective superintendent at the GNECB, which led the operation.

“The amount of money being laundered through Ireland was astronomical,” he added.

The police subsequently identified 1,000 people with links to Black Axe in Ireland and have made hundreds of arrests for fraud and cyber-crime.

“Bank robberies are now done with laptops - they’re far more sophisticated,” said Det Supt Cryan.

He estimates €200m ($220m; £170m) have been stolen online in Ireland in the past five years, and that only accounts for the 20% of cyber-crimes that are believed to be reported.

“This is not typical or ordinary crime… People who make decisions need to know how serious this is,” he said.

Irish police operations in November 2023 revealed that cryptocurrency - which can be sent rapidly between digital wallets around the world - is becoming an integral element in Black Axe’s money-laundering operations.

More than €1m in crypto-assets were seized during one operation.

Interpol has deployed its own new technology in an attempt to tackle these innovations, launching the Global Rapid Intervention of Payments system (I-GRIP).

The mechanism, which enables the authorities in member countries to freeze bank accounts around the world with unprecedented speed, was used to halt a $40m scam targeting a Singaporean business last month.

Interpol's Mr Kaya said technology like this would make it harder for criminals to move money across borders with impunity.

A major effort is under way to gather and share intelligence on Black Axe and other West African syndicates by police around the world.

“If we can gather this data we can take action,” he said.