Related Clues:

• Impostor
• White-collar crime
• Subject of an S.E.C. inquiry
• Scam
• Quack
• Duplicity
• Illegal activity
• Dupery
• Fiddle
• Whistle-blower's exposure
• Organized crime activity
• Shady financial activity
• Process involving illegal drug profits, say
• Bunco-squad concern
• Covering one's tracks, in a way