A Danbury man has been arrested on drug related charges.  The Special Investigations Division and Agents from the Drug Enforcement Administration launched an investigation several months ago into illegal sales of Fentanyl in the city based on tips from citizens. The target of the investigation was identified as 41-year old Jose Reynaldo Melendez.   Detectives were conducting surveillance Friday when Melendez left his workplace in Commerce Park and was stopped at his vehicle.  Police found 40 Fentanyl pills.  A search warrant was carried out at his East Hayestown Road apartment.  A scale, $1,000 in cash and a 2007 Acura were seized.  Melendez was charged with Possession of narcotics with intent to sell, Possession of a controlled substance, and Possession of drug paraphernalia.  He was held on $100,000 bond.