Ultimate Desires (1991)

Samantha Stewart is a successful public defender whose life gets turned upside-down one night when a prostitute named Vicki gets thrown out of a limo at Samantha's feet. Vicki slips a brooch into Sam's hand before disappering, then turns up the next day, dead. Sam soon finds herself the target of an international conspiracy who will stop at nothing to get back the brooch and silence Sam for good. To get to the bottom of the mystery (as well as to save her own skin), Sam makes the natural decision to disguise herself as a prostitute, but will it be enough?