Not necessarily.  Often, investigators want to gather more information before they talk to a person who is accused of a crime.  They can't ask questions or know when a person is being deceptive if they haven't done their homework.  Defendants have a plethora or rights under the criminal justice system, but you only have a right to know about an investigation after you are formally charged with the offense-- and then you do have a right to know what you are charged with and the right to confront your accusor.