The
black money scam, sometimes also known as the "wash wash scam", is a
scam where
con artists attempt to fraudulently obtain money from a victim by persuading him or her that piles of banknote-sized paper in a trunk or a safe is really money which has been dyed black or another color (e.g. to avoid detection by customs). The victim is persuaded to pay for chemicals to wash the "money" with a promise that he will share in the proceeds.
The black money scam is a variation of what is known as
advance fee fraud.