The Black Axe gang was involved in "multiple areas of criminal activity" globally, Bavarian police said in a statement.

In Germany, the organisation focuses on romance scams and money laundering, the force added.

The statement said: "Using false identities, the fraudsters for example signalled their intention to marry and in the course of further contact repeatedly demand money under various pretexts."

Globally, the gang's main areas of operation were "human-trafficking, fraud, money-laundering, prostitution and drug-trafficking".

The arrested suspects all hold Nigerian citizenship and are aged between 29 and 53.

They were detained on Tuesday in raids across the region of Bavaria following a police probe that lasted more than two years.

A 2021 BBC investigation of Black Axeunearthed evidence that the group had infiltrated politics in Nigeria and ran a killing operation spanning the globe.