Spanish police have detained 41 people suspected of laundering over 200m euros to finance Colombia's Farc militant insurgents.
Police also seized more than 150,000 euros during searches in 13 cities across Spain.
Investigators believe that the money was earned from smuggling drugs.
Police officers in Colombia and Ecuador have been conducting a parallel investigation and have detected a link between the money and Farc.
Spanish police searched 27 homes and offices during this operation.
A police video shows officers using sniffer dogs and finding suitcases and cupboards stuffed full of cash.
Colombia's largest guerrilla group has been fighting to overthrow the Colombian government for almost 50 years and is renowned for its involvement in drug trafficking.
WHEN THE COLOMBIAN GOVERNMENT KILLED MOMO JOJOY - THE MILITARY LEADER OF FARC - WE GOT HIS LAPTOPS AND THE INFO IN THEM IS WHY THERE HAVE BEEN SO MANY SWEEPS AND RAIDS AND ARRESTS WORLDWIDE - INCLUDING THE USA - ( INCLUDING MANY LONGTIME ALLIES OF BARACK HUSSEIN OBAMA).
ALL LEFTISTS. ALL AIDING AND ABETTING TERROR.
I PRAY THEY GET WHAT THEY DESERVE.