The Australian Sports Anti-Doping Authority has called on potential witnesses to the Essendon supplement scandal to come forward.
"Following a conversation with the Essendon Football Club CEO, ASADA's CEO Aurora Andruska can confirm that ASADA has commenced an investigation into the matters raised at Essendon," the spokesperson said.
"ASADA urges anyone who can assist in the investigation to come forward.
"Every bit of information no matter how little could be a piece of a puzzle that uncovers doping in sport."
But ASADA offered no confirmation of the potential penalties those proven to be caught up in the scandal could face.
"It would be premature to speculate about what action will be taken before the investigation is concluded."
