The Jamaica Anti-Doping Commission made the announcement on Friday.
It says all the athletes have been notified.
JADCO says it will refer the findings to the Jamaican Anti-Doping disciplinary panel and hearings will be scheduled.
The agent for Powell and Simpson did not immediately respond to an email seeking comment.
Meanwhile, local media say a Jamaican disciplinary panel is deliberating after a four-day hearing on a positive doping test by three-time Olympic gold medalist Veronica Campbell-Brown.