U.S. prosecutors contend that a $50 million international stock-manipulation scam went bust when an undercover FBI agent was offered a Picasso to launder illicit profits.

Six people and four companies have been named in the indictment handed down in Brooklyn, New York, on Monday.

“The defendants engaged in an elaborate multi-year scheme to defraud the investing public of millions of dollars through deceit and manipulative stock trading, and then worked to launder the fraudulent proceeds through off-shore bank accounts and the art world,” U.S. Attorney Richard Donoghue in Brooklyn said in a statement.

The Picasso painting, Personnage, 1965, was to be sold for $6.7 million pounds ($9.2 million) as part of the money laundering scheme. The suit alleges that British art dealer Matthew Green, the owner of Mayfair Fine Art, was arranging the sale with an undercover FBI agent. Green is now being detained in the U.S. He is the son of prominent art dealer Richard Green.