(Photo : Photo by ROBYN BECK/AFP via Getty Images)
Unsuspecting victims were taken to legal cannabis plantations to lure them into the scam, said authorities.

Police in Spain have arrested members of a gang accused of defrauding victims from 35 countries of $686 million in a scam investment in cannabis plants they claimed would be used for medicinal purposes.

The Spanish National Police said that the gang set up an eleaborate marketing system and attended international cannabis fairs to lure victims.

Investors were told their capital would develop partnerships to finance the cultivation of medicinal cannabis plants, according to Spanish police, which led the operation with Europol and police forces from five other countries, Voice of America reported. 

But it was nothing but a "notorious and complex Ponzi scheme," said authorities involved in the massive bust.

"They promised victims profits of between 70% and 168% per year, depending on the species of cannabis in which they invested," said Silvia Garrido, a sppokesoman for the Spanish police.

The British National Crime Agency said 180,000 people invested money in the scam, which it referred to as "JuicyFields."

Luxury cars, hotel parties, and music videos were allegedly used as advertising tools to help bring victims to legal cannabis plantations that were involved in the operation. 

Nine unnamed suspects were arrested April 11 on fraud charges in Spain, Britain, Germany, Latvia, Poland, Italy, and the Dominican Republic.