confederates

/K AH0 N F EH1 D ER0 AH0 T S/
noun
  1. 1

    A member of a confederacy.

  2. 2

    An accomplice in a plot.

  3. 3

    An actor who participates in a psychological experiment pretending to be a subject but in actuality working for the researcher (also known as a "stooge").

Source: https://en.wiktionary.org/wiki/confederate, https://en.wiktionary.org/wiki/confederates