Gerry 'The Monk' Hutch is due to appear in court in Lanzarote.
The 61 year-old was arrested on the island on Wednesday, as part of an investigation into suspected money laundering that targeted the Hutch organised crime group.
Ten searches were carried out in Spain, while a house in Clontarf in Dublin was raided after Spanish authorities sent a Letter of Request.
Garda Commissioner says officers here have been working with Spanish police for two years to investigate the Hutch crime gang.
Crime Journalist based in Spain, Gerard Couzens, said exact nature of the charges facing Gerry Hutch will become clearer following the court appearance.
"Differing information being given out.
"I understand that in Ireland, they're saying that it's a money laundering investigation.
"Spanish authorities are speaking about drugs trafficking and human trafficking, which was a bit of a surprise yesterday.
"We'll really have to wait and see until more information is released as to the exact nature of the allegations against each one of the individuals concerned".
