The Red-Light Sting (1984)

They paid $450,000 for a Whorehouse just to catch an Extortionist!

Government agent Frank Powell is determined to bring down racketeering crime lord Oliver Sully but cannot find any evidence. Powell concocts a plan to have the Justice Department buy a brothel, set up a professional call girl named Kathy Dunn as a hostess, and get the crime boss on extortion.